401k Plan data: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN plan

ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 401k Plan overview

Plan Name	ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN
Plan identification number	005

ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN Benefits

401k Plan Type

Defined Contribution Pension

Plan Features/Benefits

Age/Service Weighted or new comparability or similar plan - Age/Service Weighted Plan: Allocations are based on age, service, or age and service. New comparability or similar plan: Allocations are based on participant classifications and a classification(s) consists entirely or predominantly of highly compensated employees; or the plan provides an additional allocation rate on compensation above a specified threshold, and the theshold or additional rate exceeds the maximum threshold or rate allowed under the permitted disparity rules of section 401(l).
Profit-sharing
ERISA section 404(c) Plan - This plan, or any part of it is intended to meet the conditions of 29 CFR 2550.404c-1.
Partial participant-directed account plan - Participants have the opportunity to direct the investment of a portion of the assets allocated to their individual accounts, regardless of whether 29 CFR 2550.404c-1 is intended to be met.
Code section 401(k) feature - A cash or deferred arrangement described in Code section 401(k) that is part of a qualified defined contribution plan that provides for an election by employees to defer part of their compensation or receive these amounts in cash.
Code section 401(m) arrangement - Employee contributions are allocated to separate accounts under the plan or employer contributions are based, in whole or in part, on employee deferrals or contribtions to the plan. Not applicable if plan is 401(k) plan with only QNECs and/or QMACs. Also not applicable if Code section 403(b)(1), 403(b)(7) or 408 arrangements/accounts/annuities.
ESOP other than a leveraged ESOP - A completed Schedule E must be attached to a Form 5500 filed for an Employee Stock Ownership Plan (ESOP).
Participant-directed brokerage accounts provided as an investment option under the plan.
Plan provides for automatic enrollment in plan that has employee contributions deducted from payroll.
Total or partial participant-directed account plan - plan uses default investment account for participants who fail to direct assets in their account.
Plan sponsor(s) is (are) a member(s) of a controlled group (Code sections 414(b), (c), or (m)).

401k Sponsoring company profile

ALLIANT ENERGY CORPORATE SERVICES, INC. has sponsored the creation of one or more 401k plans.

Company Name: ALLIANT ENERGY CORPORATE SERVICES, INC.

Employer identification number (EIN): 391914946

NAIC Classification: 221100

Additional information about ALLIANT ENERGY CORPORATE SERVICES, INC.

Jurisdiction of Incorporation: Iowa Secretary of State Business Entities

Incorporation Date: 1997-12-08

Company Identification Number: 212193

Legal Registered Office Address: 505 5TH AVE STE 729

DES MOINES
United States of America (USA)
50309

More information about ALLIANT ENERGY CORPORATE SERVICES, INC.

Form 5500 Filing Information

Submission information for form 5500 for 401k plan ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN

Plan id# Filing Submission Date Name of Administrator Date Administrator Signed Name of Company Sponsor Date Sponsor Signed
005 2022-01-01 L. DIANE COOKE 2023-10-03 L. DIANE COOKE 2023-10-03
005 2021-01-01 L. DIANE COOKE 2022-10-09 L. DIANE COOKE 2022-10-09
005 2020-01-01 L. DIANE COOKE 2021-10-09 L. DIANE COOKE 2021-10-09
005 2019-01-01 L. DIANE COOKE 2020-10-11 L. DIANE COOKE 2020-10-11
005 2018-01-01 L. DIANE COOKE 2019-10-06 L. DIANE COOKE 2019-10-06
005 2017-01-01
005 2016-01-01
005 2015-01-01 WAYNE A. RESCHKE
005 2014-01-01 WAYNE A. RESCHKE
005 2013-01-01 WAYNE A. RESCHKE
005 2012-01-01 WAYNE A. RESCHKE
005 2011-01-01 WAYNE A. RESCHKE
005 2009-01-01 WAYNE RESCHKE WAYNE RESCHKE 2010-10-05

Plan id#	Filing Submission Date	Name of Administrator	Date Administrator Signed	Name of Company Sponsor	Date Sponsor Signed
005	2022-01-01	L. DIANE COOKE	2023-10-03	L. DIANE COOKE	2023-10-03
005	2021-01-01	L. DIANE COOKE	2022-10-09	L. DIANE COOKE	2022-10-09
005	2020-01-01	L. DIANE COOKE	2021-10-09	L. DIANE COOKE	2021-10-09
005	2019-01-01	L. DIANE COOKE	2020-10-11	L. DIANE COOKE	2020-10-11
005	2018-01-01	L. DIANE COOKE	2019-10-06	L. DIANE COOKE	2019-10-06
005	2017-01-01
005	2016-01-01
005	2015-01-01	WAYNE A. RESCHKE
005	2014-01-01	WAYNE A. RESCHKE
005	2013-01-01	WAYNE A. RESCHKE
005	2012-01-01	WAYNE A. RESCHKE
005	2011-01-01	WAYNE A. RESCHKE
005	2009-01-01	WAYNE RESCHKE		WAYNE RESCHKE	2010-10-05

Plan Statistics for ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN

401k plan membership statisitcs for ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN

Measure Date Value
2022: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2022 401k membership
Total participants, beginning-of-year 2022-01-01 4,522
Total number of active participants reported on line 7a of the Form 5500 2022-01-01 3,101
Number of retired or separated participants receiving benefits 2022-01-01 275
Number of other retired or separated participants entitled to future benefits 2022-01-01 1,016
Total of all active and inactive participants 2022-01-01 4,392
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2022-01-01 38
Total participants 2022-01-01 4,430
Number of participants with account balances 2022-01-01 4,403
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2022-01-01 29
2021: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2021 401k membership
Total participants, beginning-of-year 2021-01-01 4,586
Total number of active participants reported on line 7a of the Form 5500 2021-01-01 3,263
Number of retired or separated participants receiving benefits 2021-01-01 269
Number of other retired or separated participants entitled to future benefits 2021-01-01 961
Total of all active and inactive participants 2021-01-01 4,493
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2021-01-01 29
Total participants 2021-01-01 4,522
Number of participants with account balances 2021-01-01 4,503
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2021-01-01 75
2020: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2020 401k membership
Total participants, beginning-of-year 2020-01-01 4,716
Total number of active participants reported on line 7a of the Form 5500 2020-01-01 3,361
Number of retired or separated participants receiving benefits 2020-01-01 211
Number of other retired or separated participants entitled to future benefits 2020-01-01 983
Total of all active and inactive participants 2020-01-01 4,555
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2020-01-01 31
Total participants 2020-01-01 4,586
Number of participants with account balances 2020-01-01 4,560
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2020-01-01 33
2019: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2019 401k membership
Total participants, beginning-of-year 2019-01-01 4,900
Total number of active participants reported on line 7a of the Form 5500 2019-01-01 3,554
Number of retired or separated participants receiving benefits 2019-01-01 265
Number of other retired or separated participants entitled to future benefits 2019-01-01 868
Total of all active and inactive participants 2019-01-01 4,687
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2019-01-01 24
Total participants 2019-01-01 4,711
Number of participants with account balances 2019-01-01 4,687
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2019-01-01 60
2018: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2018 401k membership
Total participants, beginning-of-year 2018-01-01 4,979
Total number of active participants reported on line 7a of the Form 5500 2018-01-01 3,834
Number of retired or separated participants receiving benefits 2018-01-01 235
Number of other retired or separated participants entitled to future benefits 2018-01-01 817
Total of all active and inactive participants 2018-01-01 4,886
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2018-01-01 14
Total participants 2018-01-01 4,900
Number of participants with account balances 2018-01-01 4,875
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2018-01-01 49
2017: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2017 401k membership
Total participants, beginning-of-year 2017-01-01 4,923
Total number of active participants reported on line 7a of the Form 5500 2017-01-01 3,936
Number of retired or separated participants receiving benefits 2017-01-01 213
Number of other retired or separated participants entitled to future benefits 2017-01-01 818
Total of all active and inactive participants 2017-01-01 4,967
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2017-01-01 12
Total participants 2017-01-01 4,979
Number of participants with account balances 2017-01-01 4,958
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2017-01-01 42
2016: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2016 401k membership
Total participants, beginning-of-year 2016-01-01 5,173
Total number of active participants reported on line 7a of the Form 5500 2016-01-01 3,921
Number of retired or separated participants receiving benefits 2016-01-01 227
Number of other retired or separated participants entitled to future benefits 2016-01-01 767
Total of all active and inactive participants 2016-01-01 4,915
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2016-01-01 8
Total participants 2016-01-01 4,923
Number of participants with account balances 2016-01-01 4,903
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2016-01-01 37
2015: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2015 401k membership
Total participants, beginning-of-year 2015-01-01 5,162
Total number of active participants reported on line 7a of the Form 5500 2015-01-01 4,018
Number of retired or separated participants receiving benefits 2015-01-01 341
Number of other retired or separated participants entitled to future benefits 2015-01-01 775
Total of all active and inactive participants 2015-01-01 5,134
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2015-01-01 21
Total participants 2015-01-01 5,155
Number of participants with account balances 2015-01-01 5,133
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2015-01-01 77
2014: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2014 401k membership
Total participants, beginning-of-year 2014-01-01 4,904
Total number of active participants reported on line 7a of the Form 5500 2014-01-01 4,149
Number of retired or separated participants receiving benefits 2014-01-01 292
Number of other retired or separated participants entitled to future benefits 2014-01-01 708
Total of all active and inactive participants 2014-01-01 5,149
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2014-01-01 13
Total participants 2014-01-01 5,162
Number of participants with account balances 2014-01-01 5,140
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2014-01-01 84
2013: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2013 401k membership
Total participants, beginning-of-year 2013-01-01 4,858
Total number of active participants reported on line 7a of the Form 5500 2013-01-01 3,895
Number of retired or separated participants receiving benefits 2013-01-01 272
Number of other retired or separated participants entitled to future benefits 2013-01-01 721
Total of all active and inactive participants 2013-01-01 4,888
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2013-01-01 16
Total participants 2013-01-01 4,904
Number of participants with account balances 2013-01-01 4,888
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2013-01-01 55
2012: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2012 401k membership
Total participants, beginning-of-year 2012-01-01 4,949
Total number of active participants reported on line 7a of the Form 5500 2012-01-01 3,875
Number of retired or separated participants receiving benefits 2012-01-01 237
Number of other retired or separated participants entitled to future benefits 2012-01-01 735
Total of all active and inactive participants 2012-01-01 4,847
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2012-01-01 11
Total participants 2012-01-01 4,858
Number of participants with account balances 2012-01-01 4,843
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2012-01-01 44
2011: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2011 401k membership
Total participants, beginning-of-year 2011-01-01 5,074
Total number of active participants reported on line 7a of the Form 5500 2011-01-01 3,919
Number of retired or separated participants receiving benefits 2011-01-01 228
Number of other retired or separated participants entitled to future benefits 2011-01-01 790
Total of all active and inactive participants 2011-01-01 4,937
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2011-01-01 12
Total participants 2011-01-01 4,949
Number of participants with account balances 2011-01-01 4,932
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2011-01-01 60
2009: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2009 401k membership
Total participants, beginning-of-year 2009-01-01 5,418
Total number of active participants reported on line 7a of the Form 5500 2009-01-01 4,247
Number of retired or separated participants receiving benefits 2009-01-01 121
Number of other retired or separated participants entitled to future benefits 2009-01-01 840
Total of all active and inactive participants 2009-01-01 5,208
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits 2009-01-01 3
Total participants 2009-01-01 5,211
Number of participants with account balances 2009-01-01 5,130
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested 2009-01-01 102

Measure	Date	Value
2022: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2022 401k membership
Total participants, beginning-of-year	2022-01-01	4,522
Total number of active participants reported on line 7a of the Form 5500	2022-01-01	3,101
Number of retired or separated participants receiving benefits	2022-01-01	275
Number of other retired or separated participants entitled to future benefits	2022-01-01	1,016
Total of all active and inactive participants	2022-01-01	4,392
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2022-01-01	38
Total participants	2022-01-01	4,430
Number of participants with account balances	2022-01-01	4,403
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2022-01-01	29
2021: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2021 401k membership
Total participants, beginning-of-year	2021-01-01	4,586
Total number of active participants reported on line 7a of the Form 5500	2021-01-01	3,263
Number of retired or separated participants receiving benefits	2021-01-01	269
Number of other retired or separated participants entitled to future benefits	2021-01-01	961
Total of all active and inactive participants	2021-01-01	4,493
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2021-01-01	29
Total participants	2021-01-01	4,522
Number of participants with account balances	2021-01-01	4,503
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2021-01-01	75
2020: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2020 401k membership
Total participants, beginning-of-year	2020-01-01	4,716
Total number of active participants reported on line 7a of the Form 5500	2020-01-01	3,361
Number of retired or separated participants receiving benefits	2020-01-01	211
Number of other retired or separated participants entitled to future benefits	2020-01-01	983
Total of all active and inactive participants	2020-01-01	4,555
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2020-01-01	31
Total participants	2020-01-01	4,586
Number of participants with account balances	2020-01-01	4,560
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2020-01-01	33
2019: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2019 401k membership
Total participants, beginning-of-year	2019-01-01	4,900
Total number of active participants reported on line 7a of the Form 5500	2019-01-01	3,554
Number of retired or separated participants receiving benefits	2019-01-01	265
Number of other retired or separated participants entitled to future benefits	2019-01-01	868
Total of all active and inactive participants	2019-01-01	4,687
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2019-01-01	24
Total participants	2019-01-01	4,711
Number of participants with account balances	2019-01-01	4,687
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2019-01-01	60
2018: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2018 401k membership
Total participants, beginning-of-year	2018-01-01	4,979
Total number of active participants reported on line 7a of the Form 5500	2018-01-01	3,834
Number of retired or separated participants receiving benefits	2018-01-01	235
Number of other retired or separated participants entitled to future benefits	2018-01-01	817
Total of all active and inactive participants	2018-01-01	4,886
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2018-01-01	14
Total participants	2018-01-01	4,900
Number of participants with account balances	2018-01-01	4,875
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2018-01-01	49
2017: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2017 401k membership
Total participants, beginning-of-year	2017-01-01	4,923
Total number of active participants reported on line 7a of the Form 5500	2017-01-01	3,936
Number of retired or separated participants receiving benefits	2017-01-01	213
Number of other retired or separated participants entitled to future benefits	2017-01-01	818
Total of all active and inactive participants	2017-01-01	4,967
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2017-01-01	12
Total participants	2017-01-01	4,979
Number of participants with account balances	2017-01-01	4,958
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2017-01-01	42
2016: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2016 401k membership
Total participants, beginning-of-year	2016-01-01	5,173
Total number of active participants reported on line 7a of the Form 5500	2016-01-01	3,921
Number of retired or separated participants receiving benefits	2016-01-01	227
Number of other retired or separated participants entitled to future benefits	2016-01-01	767
Total of all active and inactive participants	2016-01-01	4,915
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2016-01-01	8
Total participants	2016-01-01	4,923
Number of participants with account balances	2016-01-01	4,903
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2016-01-01	37
2015: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2015 401k membership
Total participants, beginning-of-year	2015-01-01	5,162
Total number of active participants reported on line 7a of the Form 5500	2015-01-01	4,018
Number of retired or separated participants receiving benefits	2015-01-01	341
Number of other retired or separated participants entitled to future benefits	2015-01-01	775
Total of all active and inactive participants	2015-01-01	5,134
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2015-01-01	21
Total participants	2015-01-01	5,155
Number of participants with account balances	2015-01-01	5,133
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2015-01-01	77
2014: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2014 401k membership
Total participants, beginning-of-year	2014-01-01	4,904
Total number of active participants reported on line 7a of the Form 5500	2014-01-01	4,149
Number of retired or separated participants receiving benefits	2014-01-01	292
Number of other retired or separated participants entitled to future benefits	2014-01-01	708
Total of all active and inactive participants	2014-01-01	5,149
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2014-01-01	13
Total participants	2014-01-01	5,162
Number of participants with account balances	2014-01-01	5,140
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2014-01-01	84
2013: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2013 401k membership
Total participants, beginning-of-year	2013-01-01	4,858
Total number of active participants reported on line 7a of the Form 5500	2013-01-01	3,895
Number of retired or separated participants receiving benefits	2013-01-01	272
Number of other retired or separated participants entitled to future benefits	2013-01-01	721
Total of all active and inactive participants	2013-01-01	4,888
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2013-01-01	16
Total participants	2013-01-01	4,904
Number of participants with account balances	2013-01-01	4,888
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2013-01-01	55
2012: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2012 401k membership
Total participants, beginning-of-year	2012-01-01	4,949
Total number of active participants reported on line 7a of the Form 5500	2012-01-01	3,875
Number of retired or separated participants receiving benefits	2012-01-01	237
Number of other retired or separated participants entitled to future benefits	2012-01-01	735
Total of all active and inactive participants	2012-01-01	4,847
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2012-01-01	11
Total participants	2012-01-01	4,858
Number of participants with account balances	2012-01-01	4,843
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2012-01-01	44
2011: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2011 401k membership
Total participants, beginning-of-year	2011-01-01	5,074
Total number of active participants reported on line 7a of the Form 5500	2011-01-01	3,919
Number of retired or separated participants receiving benefits	2011-01-01	228
Number of other retired or separated participants entitled to future benefits	2011-01-01	790
Total of all active and inactive participants	2011-01-01	4,937
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2011-01-01	12
Total participants	2011-01-01	4,949
Number of participants with account balances	2011-01-01	4,932
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2011-01-01	60
2009: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2009 401k membership
Total participants, beginning-of-year	2009-01-01	5,418
Total number of active participants reported on line 7a of the Form 5500	2009-01-01	4,247
Number of retired or separated participants receiving benefits	2009-01-01	121
Number of other retired or separated participants entitled to future benefits	2009-01-01	840
Total of all active and inactive participants	2009-01-01	5,208
Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits	2009-01-01	3
Total participants	2009-01-01	5,211
Number of participants with account balances	2009-01-01	5,130
Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested	2009-01-01	102

Financial Data on ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN

Measure	Date	Value
2022 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2022 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2022-12-31	$-12,665,373
Total unrealized appreciation/depreciation of assets	2022-12-31	$-12,665,373
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2022-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2022-12-31	$0
Total income from all sources (including contributions)	2022-12-31	$-196,374,069
Total loss/gain on sale of assets	2022-12-31	$-805,429
Total of all expenses incurred	2022-12-31	$150,652,950
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2022-12-31	$149,635,036
Expenses. Certain deemed distributions of participant loans	2022-12-31	$151,778
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2022-12-31	$71,256,184
Value of total assets at end of year	2022-12-31	$1,166,041,158
Value of total assets at beginning of year	2022-12-31	$1,513,068,177
Total of administrative expenses incurred including professional, contract, advisory and management fees	2022-12-31	$866,136
Total interest from all sources	2022-12-31	$421,180
Total dividends received (eg from common stock, registered investment company shares)	2022-12-31	$15,797,920
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2022-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2022-12-31	$12,107,670
Was this plan covered by a fidelity bond	2022-12-31	Yes
Value of fidelity bond cover	2022-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2022-12-31	No
Were there any nonexempt tranactions with any party-in-interest	2022-12-31	No
Contributions received from participants	2022-12-31	$41,543,242
Participant contributions at end of year	2022-12-31	$7,608,906
Participant contributions at beginning of year	2022-12-31	$7,917,417
Assets. Other investments not covered elsewhere at end of year	2022-12-31	$11,254,727
Assets. Other investments not covered elsewhere at beginning of year	2022-12-31	$13,726,357
Income. Received or receivable in cash from other sources (including rollovers)	2022-12-31	$2,151,725
Other income not declared elsewhere	2022-12-31	$-2,290,895
Administrative expenses (other) incurred	2022-12-31	$866,136
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2022-12-31	No
Value of net income/loss	2022-12-31	$-347,027,019
Value of net assets at end of year (total assets less liabilities)	2022-12-31	$1,166,041,158
Value of net assets at beginning of year (total assets less liabilities)	2022-12-31	$1,513,068,177
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2022-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2022-12-31	No
Were any leases to which the plan was party in default or uncollectible	2022-12-31	No
Value of interest in registered invesment companies (eg mutual funds) at end of year	2022-12-31	$328,375,534
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2022-12-31	$442,434,637
Interest on participant loans	2022-12-31	$421,180
Value of interest in common/collective trusts at end of year	2022-12-31	$701,715,061
Value of interest in common/collective trusts at beginning of year	2022-12-31	$912,947,786
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2022-12-31	$-81,174,705
Net investment gain or loss from common/collective trusts	2022-12-31	$-186,912,951
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2022-12-31	No
Was there a failure to transmit to the plan any participant contributions	2022-12-31	No
Has the plan failed to provide any benefit when due under the plan	2022-12-31	No
Assets. Invements in employer securities at end of year	2022-12-31	$116,328,445
Assets. Invements in employer securities at beginning of year	2022-12-31	$135,268,390
Contributions received in cash from employer	2022-12-31	$27,561,217
Employer contributions (assets) at end of year	2022-12-31	$758,485
Employer contributions (assets) at beginning of year	2022-12-31	$773,590
Income. Dividends from common stock	2022-12-31	$3,690,250
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2022-12-31	$149,635,036
Did the plan have assets held for investment	2022-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2022-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2022-12-31	No
Aggregate proceeds on sale of assets	2022-12-31	$19,542,014
Aggregate carrying amount (costs) on sale of assets	2022-12-31	$20,347,443
Opinion of an independent qualified public accountant for this plan	2022-12-31	Unqualified
Accountancy firm name	2022-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2022-12-31	133891517
2021 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2021 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2021-12-31	$21,282,865
Total unrealized appreciation/depreciation of assets	2021-12-31	$21,282,865
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2021-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2021-12-31	$0
Total income from all sources (including contributions)	2021-12-31	$262,562,920
Total loss/gain on sale of assets	2021-12-31	$1,564,308
Total of all expenses incurred	2021-12-31	$138,792,553
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2021-12-31	$137,721,898
Expenses. Certain deemed distributions of participant loans	2021-12-31	$151,551
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2021-12-31	$69,147,807
Value of total assets at end of year	2021-12-31	$1,513,068,177
Value of total assets at beginning of year	2021-12-31	$1,389,297,810
Total of administrative expenses incurred including professional, contract, advisory and management fees	2021-12-31	$919,104
Total interest from all sources	2021-12-31	$463,690
Total dividends received (eg from common stock, registered investment company shares)	2021-12-31	$31,708,361
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2021-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2021-12-31	$28,007,690
Was this plan covered by a fidelity bond	2021-12-31	Yes
Value of fidelity bond cover	2021-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2021-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2021-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2021-12-31	No
Contributions received from participants	2021-12-31	$41,247,455
Participant contributions at end of year	2021-12-31	$7,917,417
Participant contributions at beginning of year	2021-12-31	$8,326,409
Assets. Other investments not covered elsewhere at end of year	2021-12-31	$13,726,357
Assets. Other investments not covered elsewhere at beginning of year	2021-12-31	$9,696,723
Income. Received or receivable in cash from other sources (including rollovers)	2021-12-31	$1,647,981
Other income not declared elsewhere	2021-12-31	$1,483,833
Administrative expenses (other) incurred	2021-12-31	$919,104
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2021-12-31	No
Value of net income/loss	2021-12-31	$123,770,367
Value of net assets at end of year (total assets less liabilities)	2021-12-31	$1,513,068,177
Value of net assets at beginning of year (total assets less liabilities)	2021-12-31	$1,389,297,810
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2021-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2021-12-31	No
Were any leases to which the plan was party in default or uncollectible	2021-12-31	No
Value of interest in registered invesment companies (eg mutual funds) at end of year	2021-12-31	$442,434,637
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2021-12-31	$425,303,646
Interest on participant loans	2021-12-31	$463,690
Value of interest in common/collective trusts at end of year	2021-12-31	$912,947,786
Value of interest in common/collective trusts at beginning of year	2021-12-31	$821,700,538
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2021-12-31	$13,966,639
Net investment gain or loss from common/collective trusts	2021-12-31	$122,945,417
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2021-12-31	No
Was there a failure to transmit to the plan any participant contributions	2021-12-31	No
Has the plan failed to provide any benefit when due under the plan	2021-12-31	No
Assets. Invements in employer securities at end of year	2021-12-31	$135,268,390
Assets. Invements in employer securities at beginning of year	2021-12-31	$123,589,889
Contributions received in cash from employer	2021-12-31	$26,252,371
Employer contributions (assets) at end of year	2021-12-31	$773,590
Employer contributions (assets) at beginning of year	2021-12-31	$680,605
Income. Dividends from common stock	2021-12-31	$3,700,671
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2021-12-31	$137,721,898
Did the plan have assets held for investment	2021-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2021-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2021-12-31	No
Aggregate proceeds on sale of assets	2021-12-31	$22,731,163
Aggregate carrying amount (costs) on sale of assets	2021-12-31	$21,166,855
Opinion of an independent qualified public accountant for this plan	2021-12-31	Unqualified
Accountancy firm name	2021-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2021-12-31	133891517
2020 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2020 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2020-12-31	$-7,153,346
Total unrealized appreciation/depreciation of assets	2020-12-31	$-7,153,346
Total transfer of assets to this plan	2020-12-31	$1,557,814
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2020-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2020-12-31	$0
Total income from all sources (including contributions)	2020-12-31	$264,933,167
Total loss/gain on sale of assets	2020-12-31	$-280,478
Total of all expenses incurred	2020-12-31	$114,338,021
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2020-12-31	$113,204,421
Expenses. Certain deemed distributions of participant loans	2020-12-31	$276,712
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2020-12-31	$67,924,196
Value of total assets at end of year	2020-12-31	$1,389,297,810
Value of total assets at beginning of year	2020-12-31	$1,237,144,850
Total of administrative expenses incurred including professional, contract, advisory and management fees	2020-12-31	$856,888
Total interest from all sources	2020-12-31	$554,065
Total dividends received (eg from common stock, registered investment company shares)	2020-12-31	$16,938,324
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2020-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2020-12-31	$13,168,040
Was this plan covered by a fidelity bond	2020-12-31	Yes
Value of fidelity bond cover	2020-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2020-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2020-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2020-12-31	No
Contributions received from participants	2020-12-31	$40,537,304
Participant contributions at end of year	2020-12-31	$8,326,409
Participant contributions at beginning of year	2020-12-31	$9,750,617
Assets. Other investments not covered elsewhere at end of year	2020-12-31	$9,696,723
Assets. Other investments not covered elsewhere at beginning of year	2020-12-31	$6,690,082
Income. Received or receivable in cash from other sources (including rollovers)	2020-12-31	$1,782,779
Other income not declared elsewhere	2020-12-31	$3,332,401
Administrative expenses (other) incurred	2020-12-31	$856,888
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2020-12-31	No
Value of net income/loss	2020-12-31	$150,595,146
Value of net assets at end of year (total assets less liabilities)	2020-12-31	$1,389,297,810
Value of net assets at beginning of year (total assets less liabilities)	2020-12-31	$1,237,144,850
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2020-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2020-12-31	No
Were any leases to which the plan was party in default or uncollectible	2020-12-31	No
Value of interest in registered invesment companies (eg mutual funds) at end of year	2020-12-31	$425,303,646
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2020-12-31	$516,626,068
Interest on participant loans	2020-12-31	$554,065
Value of interest in common/collective trusts at end of year	2020-12-31	$821,700,538
Value of interest in common/collective trusts at beginning of year	2020-12-31	$562,686,121
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2020-12-31	$54,303,599
Net investment gain or loss from common/collective trusts	2020-12-31	$129,314,406
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2020-12-31	No
Was there a failure to transmit to the plan any participant contributions	2020-12-31	No
Has the plan failed to provide any benefit when due under the plan	2020-12-31	No
Assets. Invements in employer securities at end of year	2020-12-31	$123,589,889
Assets. Invements in employer securities at beginning of year	2020-12-31	$140,819,249
Contributions received in cash from employer	2020-12-31	$25,604,113
Employer contributions (assets) at end of year	2020-12-31	$680,605
Employer contributions (assets) at beginning of year	2020-12-31	$572,713
Income. Dividends from common stock	2020-12-31	$3,770,284
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2020-12-31	$113,204,421
Did the plan have assets held for investment	2020-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2020-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2020-12-31	No
Aggregate proceeds on sale of assets	2020-12-31	$26,110,775
Aggregate carrying amount (costs) on sale of assets	2020-12-31	$26,391,253
Opinion of an independent qualified public accountant for this plan	2020-12-31	Unqualified
Accountancy firm name	2020-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2020-12-31	133891517
2019 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2019 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2019-12-31	$30,886,344
Total unrealized appreciation/depreciation of assets	2019-12-31	$30,886,344
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2019-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2019-12-31	$0
Total income from all sources (including contributions)	2019-12-31	$316,334,064
Total loss/gain on sale of assets	2019-12-31	$2,937,622
Total of all expenses incurred	2019-12-31	$113,539,633
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2019-12-31	$112,373,214
Expenses. Certain deemed distributions of participant loans	2019-12-31	$302,978
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2019-12-31	$69,208,080
Value of total assets at end of year	2019-12-31	$1,237,144,850
Value of total assets at beginning of year	2019-12-31	$1,034,350,419
Total of administrative expenses incurred including professional, contract, advisory and management fees	2019-12-31	$863,441
Total interest from all sources	2019-12-31	$536,982
Total dividends received (eg from common stock, registered investment company shares)	2019-12-31	$32,366,309
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2019-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2019-12-31	$28,530,592
Was this plan covered by a fidelity bond	2019-12-31	Yes
Value of fidelity bond cover	2019-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2019-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2019-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2019-12-31	No
Contributions received from participants	2019-12-31	$39,596,546
Participant contributions at end of year	2019-12-31	$9,750,617
Participant contributions at beginning of year	2019-12-31	$9,433,904
Assets. Other investments not covered elsewhere at end of year	2019-12-31	$6,690,082
Assets. Other investments not covered elsewhere at beginning of year	2019-12-31	$6,114,601
Income. Received or receivable in cash from other sources (including rollovers)	2019-12-31	$3,978,814
Other income not declared elsewhere	2019-12-31	$2,843,272
Administrative expenses (other) incurred	2019-12-31	$863,441
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2019-12-31	No
Value of net income/loss	2019-12-31	$202,794,431
Value of net assets at end of year (total assets less liabilities)	2019-12-31	$1,237,144,850
Value of net assets at beginning of year (total assets less liabilities)	2019-12-31	$1,034,350,419
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2019-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2019-12-31	No
Were any leases to which the plan was party in default or uncollectible	2019-12-31	No
Value of interest in registered invesment companies (eg mutual funds) at end of year	2019-12-31	$516,626,068
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2019-12-31	$428,729,612
Interest on participant loans	2019-12-31	$536,982
Value of interest in common/collective trusts at end of year	2019-12-31	$562,686,121
Value of interest in common/collective trusts at beginning of year	2019-12-31	$471,361,528
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2019-12-31	$71,650,320
Net investment gain or loss from common/collective trusts	2019-12-31	$105,905,135
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2019-12-31	No
Was there a failure to transmit to the plan any participant contributions	2019-12-31	No
Has the plan failed to provide any benefit when due under the plan	2019-12-31	No
Assets. Invements in employer securities at end of year	2019-12-31	$140,819,249
Assets. Invements in employer securities at beginning of year	2019-12-31	$118,211,667
Contributions received in cash from employer	2019-12-31	$25,632,720
Employer contributions (assets) at end of year	2019-12-31	$572,713
Employer contributions (assets) at beginning of year	2019-12-31	$499,107
Income. Dividends from common stock	2019-12-31	$3,835,717
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2019-12-31	$112,373,214
Did the plan have assets held for investment	2019-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2019-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2019-12-31	No
Aggregate proceeds on sale of assets	2019-12-31	$2,937,622
Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d)	2019-12-31	No
Opinion of an independent qualified public accountant for this plan	2019-12-31	Unqualified
Accountancy firm name	2019-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2019-12-31	133891517
2018 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2018 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2018-12-31	$-867,696
Total unrealized appreciation/depreciation of assets	2018-12-31	$-867,696
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2018-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2018-12-31	$0
Total income from all sources (including contributions)	2018-12-31	$16,539,277
Total loss/gain on sale of assets	2018-12-31	$-264,907
Total of all expenses incurred	2018-12-31	$105,696,516
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2018-12-31	$104,700,358
Expenses. Certain deemed distributions of participant loans	2018-12-31	$134,666
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2018-12-31	$66,010,447
Value of total assets at end of year	2018-12-31	$1,034,350,419
Value of total assets at beginning of year	2018-12-31	$1,123,507,658
Total of administrative expenses incurred including professional, contract, advisory and management fees	2018-12-31	$861,492
Total interest from all sources	2018-12-31	$481,032
Total dividends received (eg from common stock, registered investment company shares)	2018-12-31	$39,363,241
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2018-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2018-12-31	$35,485,708
Was this plan covered by a fidelity bond	2018-12-31	Yes
Value of fidelity bond cover	2018-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2018-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2018-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2018-12-31	No
Contributions received from participants	2018-12-31	$38,638,140
Participant contributions at end of year	2018-12-31	$9,433,904
Participant contributions at beginning of year	2018-12-31	$9,490,837
Assets. Other investments not covered elsewhere at end of year	2018-12-31	$6,114,601
Assets. Other investments not covered elsewhere at beginning of year	2018-12-31	$7,410,602
Income. Received or receivable in cash from other sources (including rollovers)	2018-12-31	$2,226,085
Other income not declared elsewhere	2018-12-31	$707,151
Administrative expenses (other) incurred	2018-12-31	$861,492
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2018-12-31	No
Value of net income/loss	2018-12-31	$-89,157,239
Value of net assets at end of year (total assets less liabilities)	2018-12-31	$1,034,350,419
Value of net assets at beginning of year (total assets less liabilities)	2018-12-31	$1,123,507,658
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2018-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2018-12-31	No
Were any leases to which the plan was party in default or uncollectible	2018-12-31	No
Value of interest in registered invesment companies (eg mutual funds) at end of year	2018-12-31	$428,729,612
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2018-12-31	$481,111,510
Interest on participant loans	2018-12-31	$481,032
Value of interest in common/collective trusts at end of year	2018-12-31	$471,361,528
Value of interest in common/collective trusts at beginning of year	2018-12-31	$496,979,760
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2018-12-31	$-85,387,585
Net investment gain or loss from common/collective trusts	2018-12-31	$-3,502,406
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2018-12-31	No
Was there a failure to transmit to the plan any participant contributions	2018-12-31	No
Has the plan failed to provide any benefit when due under the plan	2018-12-31	No
Assets. Invements in employer securities at end of year	2018-12-31	$118,211,667
Assets. Invements in employer securities at beginning of year	2018-12-31	$127,958,394
Contributions received in cash from employer	2018-12-31	$25,146,222
Employer contributions (assets) at end of year	2018-12-31	$499,107
Employer contributions (assets) at beginning of year	2018-12-31	$556,555
Income. Dividends from common stock	2018-12-31	$3,877,533
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2018-12-31	$104,700,358
Did the plan have assets held for investment	2018-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2018-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2018-12-31	No
Aggregate proceeds on sale of assets	2018-12-31	$-264,907
Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d)	2018-12-31	No
Opinion of an independent qualified public accountant for this plan	2018-12-31	Unqualified
Accountancy firm name	2018-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2018-12-31	133891517
2017 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2017 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2017-12-31	$13,437,648
Total unrealized appreciation/depreciation of assets	2017-12-31	$13,437,648
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2017-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2017-12-31	$0
Total income from all sources (including contributions)	2017-12-31	$242,143,749
Total loss/gain on sale of assets	2017-12-31	$1,173,116
Total of all expenses incurred	2017-12-31	$85,568,677
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2017-12-31	$84,729,117
Expenses. Certain deemed distributions of participant loans	2017-12-31	$27,413
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2017-12-31	$67,848,003
Value of total assets at end of year	2017-12-31	$1,123,507,658
Value of total assets at beginning of year	2017-12-31	$966,932,586
Total of administrative expenses incurred including professional, contract, advisory and management fees	2017-12-31	$812,147
Total interest from all sources	2017-12-31	$417,036
Total dividends received (eg from common stock, registered investment company shares)	2017-12-31	$28,713,681
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2017-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2017-12-31	$24,848,591
Was this plan covered by a fidelity bond	2017-12-31	Yes
Value of fidelity bond cover	2017-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2017-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2017-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2017-12-31	No
Contributions received from participants	2017-12-31	$38,722,019
Participant contributions at end of year	2017-12-31	$9,490,837
Participant contributions at beginning of year	2017-12-31	$9,718,270
Assets. Other investments not covered elsewhere at end of year	2017-12-31	$7,410,602
Assets. Other investments not covered elsewhere at beginning of year	2017-12-31	$5,794,002
Income. Received or receivable in cash from other sources (including rollovers)	2017-12-31	$4,104,955
Other income not declared elsewhere	2017-12-31	$2,050,651
Administrative expenses (other) incurred	2017-12-31	$812,147
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2017-12-31	No
Value of net income/loss	2017-12-31	$156,575,072
Value of net assets at end of year (total assets less liabilities)	2017-12-31	$1,123,507,658
Value of net assets at beginning of year (total assets less liabilities)	2017-12-31	$966,932,586
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2017-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2017-12-31	No
Were any leases to which the plan was party in default or uncollectible	2017-12-31	No
Value of interest in registered invesment companies (eg mutual funds) at end of year	2017-12-31	$481,111,510
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2017-12-31	$391,935,828
Interest on participant loans	2017-12-31	$417,036
Value of interest in common/collective trusts at end of year	2017-12-31	$496,979,760
Value of interest in common/collective trusts at beginning of year	2017-12-31	$438,495,987
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2017-12-31	$58,303,057
Net investment gain or loss from common/collective trusts	2017-12-31	$70,200,557
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2017-12-31	No
Was there a failure to transmit to the plan any participant contributions	2017-12-31	No
Has the plan failed to provide any benefit when due under the plan	2017-12-31	No
Assets. Invements in employer securities at end of year	2017-12-31	$127,958,394
Assets. Invements in employer securities at beginning of year	2017-12-31	$120,513,373
Contributions received in cash from employer	2017-12-31	$25,021,029
Employer contributions (assets) at end of year	2017-12-31	$556,555
Employer contributions (assets) at beginning of year	2017-12-31	$475,126
Income. Dividends from common stock	2017-12-31	$3,865,090
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2017-12-31	$84,729,117
Did the plan have assets held for investment	2017-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2017-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2017-12-31	No
Aggregate proceeds on sale of assets	2017-12-31	$1,173,116
Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d)	2017-12-31	No
Opinion of an independent qualified public accountant for this plan	2017-12-31	Unqualified
Accountancy firm name	2017-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2017-12-31	133891517
2016 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2016 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2016-12-31	$12,523,636
Total unrealized appreciation/depreciation of assets	2016-12-31	$12,523,636
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2016-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2016-12-31	$0
Total income from all sources (including contributions)	2016-12-31	$142,205,445
Total loss/gain on sale of assets	2016-12-31	$9,602,699
Total of all expenses incurred	2016-12-31	$84,067,951
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2016-12-31	$83,098,005
Expenses. Certain deemed distributions of participant loans	2016-12-31	$162,246
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2016-12-31	$62,663,520
Value of total assets at end of year	2016-12-31	$966,932,586
Value of total assets at beginning of year	2016-12-31	$908,795,092
Total of administrative expenses incurred including professional, contract, advisory and management fees	2016-12-31	$807,700
Total interest from all sources	2016-12-31	$440,093
Total dividends received (eg from common stock, registered investment company shares)	2016-12-31	$16,118,033
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2016-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2016-12-31	$12,322,791
Was this plan covered by a fidelity bond	2016-12-31	Yes
Value of fidelity bond cover	2016-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2016-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2016-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2016-12-31	No
Contributions received from participants	2016-12-31	$36,743,831
Participant contributions at end of year	2016-12-31	$9,718,270
Participant contributions at beginning of year	2016-12-31	$10,019,589
Assets. Other investments not covered elsewhere at end of year	2016-12-31	$5,794,002
Assets. Other investments not covered elsewhere at beginning of year	2016-12-31	$6,205,866
Income. Received or receivable in cash from other sources (including rollovers)	2016-12-31	$2,448,930
Other income not declared elsewhere	2016-12-31	$1,367,358
Administrative expenses (other) incurred	2016-12-31	$513,744
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2016-12-31	No
Value of net income/loss	2016-12-31	$58,137,494
Value of net assets at end of year (total assets less liabilities)	2016-12-31	$966,932,586
Value of net assets at beginning of year (total assets less liabilities)	2016-12-31	$908,795,092
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2016-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2016-12-31	No
Were any leases to which the plan was party in default or uncollectible	2016-12-31	No
Investment advisory and management fees	2016-12-31	$293,956
Value of interest in registered invesment companies (eg mutual funds) at end of year	2016-12-31	$391,935,828
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2016-12-31	$346,427,524
Interest on participant loans	2016-12-31	$440,093
Value of interest in common/collective trusts at end of year	2016-12-31	$438,495,987
Value of interest in common/collective trusts at beginning of year	2016-12-31	$438,933,994
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2016-12-31	$19,870,468
Net investment gain or loss from common/collective trusts	2016-12-31	$19,619,638
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2016-12-31	No
Was there a failure to transmit to the plan any participant contributions	2016-12-31	No
Has the plan failed to provide any benefit when due under the plan	2016-12-31	No
Assets. Invements in employer securities at end of year	2016-12-31	$120,513,373
Assets. Invements in employer securities at beginning of year	2016-12-31	$105,730,131
Contributions received in cash from employer	2016-12-31	$23,470,759
Employer contributions (assets) at end of year	2016-12-31	$475,126
Employer contributions (assets) at beginning of year	2016-12-31	$1,477,988
Income. Dividends from common stock	2016-12-31	$3,795,242
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2016-12-31	$83,098,005
Did the plan have assets held for investment	2016-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2016-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2016-12-31	No
Aggregate proceeds on sale of assets	2016-12-31	$9,602,699
Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d)	2016-12-31	No
Opinion of an independent qualified public accountant for this plan	2016-12-31	Unqualified
Accountancy firm name	2016-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2016-12-31	133891517
2015 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2015 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2015-12-31	$-12,342,475
Total unrealized appreciation/depreciation of assets	2015-12-31	$-12,342,475
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2015-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2015-12-31	$0
Total income from all sources (including contributions)	2015-12-31	$58,870,261
Total loss/gain on sale of assets	2015-12-31	$5,290,759
Total of all expenses incurred	2015-12-31	$75,163,132
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2015-12-31	$74,416,395
Expenses. Certain deemed distributions of participant loans	2015-12-31	$26,381
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2015-12-31	$65,045,122
Value of total assets at end of year	2015-12-31	$908,795,092
Value of total assets at beginning of year	2015-12-31	$925,087,963
Total of administrative expenses incurred including professional, contract, advisory and management fees	2015-12-31	$720,356
Total interest from all sources	2015-12-31	$439,699
Total dividends received (eg from common stock, registered investment company shares)	2015-12-31	$21,528,868
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2015-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2015-12-31	$17,729,766
Was this plan covered by a fidelity bond	2015-12-31	Yes
Value of fidelity bond cover	2015-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2015-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2015-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2015-12-31	No
Contributions received from participants	2015-12-31	$37,089,314
Participant contributions at end of year	2015-12-31	$10,019,589
Participant contributions at beginning of year	2015-12-31	$10,441,078
Assets. Other investments not covered elsewhere at end of year	2015-12-31	$6,205,866
Assets. Other investments not covered elsewhere at beginning of year	2015-12-31	$5,717,887
Income. Received or receivable in cash from other sources (including rollovers)	2015-12-31	$2,303,499
Other income not declared elsewhere	2015-12-31	$1,226,847
Administrative expenses (other) incurred	2015-12-31	$122,674
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2015-12-31	No
Value of net income/loss	2015-12-31	$-16,292,871
Value of net assets at end of year (total assets less liabilities)	2015-12-31	$908,795,092
Value of net assets at beginning of year (total assets less liabilities)	2015-12-31	$925,087,963
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2015-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2015-12-31	No
Were any leases to which the plan was party in default or uncollectible	2015-12-31	No
Investment advisory and management fees	2015-12-31	$597,682
Value of interest in registered invesment companies (eg mutual funds) at end of year	2015-12-31	$346,427,524
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2015-12-31	$357,145,912
Interest on participant loans	2015-12-31	$439,699
Value of interest in common/collective trusts at end of year	2015-12-31	$438,933,994
Value of interest in common/collective trusts at beginning of year	2015-12-31	$435,209,255
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2015-12-31	$-29,909,818
Net investment gain or loss from common/collective trusts	2015-12-31	$7,591,259
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2015-12-31	No
Was there a failure to transmit to the plan any participant contributions	2015-12-31	No
Has the plan failed to provide any benefit when due under the plan	2015-12-31	No
Assets. Invements in employer securities at end of year	2015-12-31	$105,730,131
Assets. Invements in employer securities at beginning of year	2015-12-31	$116,573,831
Contributions received in cash from employer	2015-12-31	$25,652,309
Employer contributions (assets) at end of year	2015-12-31	$1,477,988
Employer contributions (assets) at beginning of year	2015-12-31	$0
Income. Dividends from common stock	2015-12-31	$3,799,102
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2015-12-31	$74,416,395
Did the plan have assets held for investment	2015-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2015-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2015-12-31	No
Aggregate proceeds on sale of assets	2015-12-31	$5,290,759
Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d)	2015-12-31	No
Opinion of an independent qualified public accountant for this plan	2015-12-31	Unqualified
Accountancy firm name	2015-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2015-12-31	133891517
2014 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2014 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2014-12-31	$20,183,306
Total unrealized appreciation/depreciation of assets	2014-12-31	$20,183,306
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2014-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2014-12-31	$0
Total income from all sources (including contributions)	2014-12-31	$131,481,206
Total loss/gain on sale of assets	2014-12-31	$6,636,991
Total of all expenses incurred	2014-12-31	$69,132,068
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2014-12-31	$68,442,794
Expenses. Certain deemed distributions of participant loans	2014-12-31	$30,582
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2014-12-31	$57,964,047
Value of total assets at end of year	2014-12-31	$925,087,963
Value of total assets at beginning of year	2014-12-31	$862,738,825
Total of administrative expenses incurred including professional, contract, advisory and management fees	2014-12-31	$658,692
Total interest from all sources	2014-12-31	$449,436
Total dividends received (eg from common stock, registered investment company shares)	2014-12-31	$18,329,331
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2014-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2014-12-31	$14,602,586
Was this plan covered by a fidelity bond	2014-12-31	Yes
Value of fidelity bond cover	2014-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2014-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2014-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2014-12-31	No
Contributions received from participants	2014-12-31	$33,842,248
Participant contributions at end of year	2014-12-31	$10,441,078
Participant contributions at beginning of year	2014-12-31	$10,605,870
Assets. Other investments not covered elsewhere at end of year	2014-12-31	$5,717,887
Assets. Other investments not covered elsewhere at beginning of year	2014-12-31	$4,117,755
Income. Received or receivable in cash from other sources (including rollovers)	2014-12-31	$1,955,862
Other income not declared elsewhere	2014-12-31	$1,317,566
Administrative expenses (other) incurred	2014-12-31	$77,752
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2014-12-31	No
Value of net income/loss	2014-12-31	$62,349,138
Value of net assets at end of year (total assets less liabilities)	2014-12-31	$925,087,963
Value of net assets at beginning of year (total assets less liabilities)	2014-12-31	$862,738,825
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2014-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2014-12-31	No
Were any leases to which the plan was party in default or uncollectible	2014-12-31	No
Investment advisory and management fees	2014-12-31	$580,940
Value of interest in registered invesment companies (eg mutual funds) at end of year	2014-12-31	$357,145,912
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2014-12-31	$355,316,872
Interest on participant loans	2014-12-31	$449,436
Value of interest in common/collective trusts at end of year	2014-12-31	$435,209,255
Value of interest in common/collective trusts at beginning of year	2014-12-31	$395,247,603
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2014-12-31	$-7,235,233
Net investment gain or loss from common/collective trusts	2014-12-31	$33,835,762
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2014-12-31	No
Was there a failure to transmit to the plan any participant contributions	2014-12-31	No
Has the plan failed to provide any benefit when due under the plan	2014-12-31	No
Assets. Invements in employer securities at end of year	2014-12-31	$116,573,831
Assets. Invements in employer securities at beginning of year	2014-12-31	$97,450,725
Contributions received in cash from employer	2014-12-31	$22,165,937
Income. Dividends from common stock	2014-12-31	$3,726,745
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2014-12-31	$68,442,794
Did the plan have assets held for investment	2014-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2014-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2014-12-31	No
Aggregate proceeds on sale of assets	2014-12-31	$6,636,991
Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d)	2014-12-31	No
Opinion of an independent qualified public accountant for this plan	2014-12-31	Unqualified
Accountancy firm name	2014-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2014-12-31	393891517
2013 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2013 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2013-12-31	$9,604,686
Total unrealized appreciation/depreciation of assets	2013-12-31	$9,604,686
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2013-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2013-12-31	$0
Total income from all sources (including contributions)	2013-12-31	$197,100,838
Total loss/gain on sale of assets	2013-12-31	$6,022,542
Total of all expenses incurred	2013-12-31	$62,402,581
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2013-12-31	$61,672,734
Expenses. Certain deemed distributions of participant loans	2013-12-31	$36,227
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2013-12-31	$51,850,702
Value of total assets at end of year	2013-12-31	$862,738,825
Value of total assets at beginning of year	2013-12-31	$728,040,568
Total of administrative expenses incurred including professional, contract, advisory and management fees	2013-12-31	$693,620
Total interest from all sources	2013-12-31	$468,589
Total dividends received (eg from common stock, registered investment company shares)	2013-12-31	$15,540,168
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2013-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2013-12-31	$11,824,392
Was this plan covered by a fidelity bond	2013-12-31	Yes
Value of fidelity bond cover	2013-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2013-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2013-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2013-12-31	No
Contributions received from participants	2013-12-31	$30,817,073
Participant contributions at end of year	2013-12-31	$10,605,870
Participant contributions at beginning of year	2013-12-31	$10,877,588
Assets. Other investments not covered elsewhere at end of year	2013-12-31	$4,117,755
Assets. Other investments not covered elsewhere at beginning of year	2013-12-31	$3,289,471
Income. Received or receivable in cash from other sources (including rollovers)	2013-12-31	$1,811,370
Other income not declared elsewhere	2013-12-31	$1,484,581
Administrative expenses (other) incurred	2013-12-31	$152,245
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2013-12-31	No
Value of net income/loss	2013-12-31	$134,698,257
Value of net assets at end of year (total assets less liabilities)	2013-12-31	$862,738,825
Value of net assets at beginning of year (total assets less liabilities)	2013-12-31	$728,040,568
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2013-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2013-12-31	No
Were any leases to which the plan was party in default or uncollectible	2013-12-31	No
Investment advisory and management fees	2013-12-31	$541,375
Value of interest in registered invesment companies (eg mutual funds) at end of year	2013-12-31	$355,316,872
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2013-12-31	$288,995,107
Interest on participant loans	2013-12-31	$468,589
Value of interest in common/collective trusts at end of year	2013-12-31	$395,247,603
Value of interest in common/collective trusts at beginning of year	2013-12-31	$334,356,648
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2013-12-31	$48,087,020
Net investment gain or loss from common/collective trusts	2013-12-31	$64,042,550
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2013-12-31	No
Was there a failure to transmit to the plan any participant contributions	2013-12-31	No
Has the plan failed to provide any benefit when due under the plan	2013-12-31	No
Assets. Invements in employer securities at end of year	2013-12-31	$97,450,725
Assets. Invements in employer securities at beginning of year	2013-12-31	$90,521,754
Contributions received in cash from employer	2013-12-31	$19,222,259
Income. Dividends from common stock	2013-12-31	$3,715,776
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2013-12-31	$61,672,734
Did the plan have assets held for investment	2013-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2013-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2013-12-31	No
Aggregate proceeds on sale of assets	2013-12-31	$6,022,542
Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d)	2013-12-31	No
Opinion of an independent qualified public accountant for this plan	2013-12-31	Unqualified
Accountancy firm name	2013-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2013-12-31	393891517
2012 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2012 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2012-12-31	$-4,862,419
Total unrealized appreciation/depreciation of assets	2012-12-31	$-4,862,419
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2012-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2012-12-31	$0
Total income from all sources (including contributions)	2012-12-31	$124,919,694
Total loss/gain on sale of assets	2012-12-31	$4,442,386
Total of all expenses incurred	2012-12-31	$54,944,037
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2012-12-31	$54,186,036
Expenses. Certain deemed distributions of participant loans	2012-12-31	$21,026
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2012-12-31	$48,644,337
Value of total assets at end of year	2012-12-31	$728,040,568
Value of total assets at beginning of year	2012-12-31	$658,064,911
Total of administrative expenses incurred including professional, contract, advisory and management fees	2012-12-31	$736,975
Total interest from all sources	2012-12-31	$480,791
Total dividends received (eg from common stock, registered investment company shares)	2012-12-31	$13,728,113
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2012-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2012-12-31	$9,899,789
Was this plan covered by a fidelity bond	2012-12-31	Yes
Value of fidelity bond cover	2012-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2012-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2012-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2012-12-31	No
Contributions received from participants	2012-12-31	$29,087,416
Participant contributions at end of year	2012-12-31	$10,877,588
Participant contributions at beginning of year	2012-12-31	$10,766,691
Assets. Other investments not covered elsewhere at end of year	2012-12-31	$3,289,471
Assets. Other investments not covered elsewhere at beginning of year	2012-12-31	$2,446,404
Income. Received or receivable in cash from other sources (including rollovers)	2012-12-31	$1,007,000
Other income not declared elsewhere	2012-12-31	$1,743,695
Administrative expenses (other) incurred	2012-12-31	$170,996
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2012-12-31	No
Value of net income/loss	2012-12-31	$69,975,657
Value of net assets at end of year (total assets less liabilities)	2012-12-31	$728,040,568
Value of net assets at beginning of year (total assets less liabilities)	2012-12-31	$658,064,911
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2012-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2012-12-31	No
Were any leases to which the plan was party in default or uncollectible	2012-12-31	No
Investment advisory and management fees	2012-12-31	$565,979
Value of interest in registered invesment companies (eg mutual funds) at end of year	2012-12-31	$288,995,107
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2012-12-31	$228,361,384
Interest on participant loans	2012-12-31	$480,791
Value of interest in common/collective trusts at end of year	2012-12-31	$334,356,648
Value of interest in common/collective trusts at beginning of year	2012-12-31	$319,047,680
Asset value of US Government securities at end of year	2012-12-31	$0
Asset value of US Government securities at beginning of year	2012-12-31	$1,504,581
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2012-12-31	$30,641,108
Net investment gain or loss from common/collective trusts	2012-12-31	$30,101,683
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2012-12-31	No
Was there a failure to transmit to the plan any participant contributions	2012-12-31	No
Has the plan failed to provide any benefit when due under the plan	2012-12-31	No
Assets. Invements in employer securities at end of year	2012-12-31	$90,521,754
Assets. Invements in employer securities at beginning of year	2012-12-31	$95,938,171
Contributions received in cash from employer	2012-12-31	$18,549,921
Income. Dividends from common stock	2012-12-31	$3,828,324
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2012-12-31	$54,186,036
Did the plan have assets held for investment	2012-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2012-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2012-12-31	No
Aggregate proceeds on sale of assets	2012-12-31	$4,442,386
Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d)	2012-12-31	No
Opinion of an independent qualified public accountant for this plan	2012-12-31	Unqualified
Accountancy firm name	2012-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2012-12-31	393891517
2011 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2011 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2011-12-31	$11,666,219
Total unrealized appreciation/depreciation of assets	2011-12-31	$11,666,219
Total transfer of assets to this plan	2011-12-31	$1,880,050
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2011-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2011-12-31	$0
Total income from all sources (including contributions)	2011-12-31	$56,841,357
Total loss/gain on sale of assets	2011-12-31	$4,597,984
Total of all expenses incurred	2011-12-31	$65,273,004
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2011-12-31	$64,614,560
Expenses. Certain deemed distributions of participant loans	2011-12-31	$42,545
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2011-12-31	$48,173,044
Value of total assets at end of year	2011-12-31	$658,064,911
Value of total assets at beginning of year	2011-12-31	$664,616,508
Total of administrative expenses incurred including professional, contract, advisory and management fees	2011-12-31	$615,899
Total interest from all sources	2011-12-31	$584,510
Total dividends received (eg from common stock, registered investment company shares)	2011-12-31	$9,617,945
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2011-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2011-12-31	$5,832,749
Was this plan covered by a fidelity bond	2011-12-31	Yes
Value of fidelity bond cover	2011-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2011-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2011-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2011-12-31	No
Contributions received from participants	2011-12-31	$29,157,305
Participant contributions at end of year	2011-12-31	$10,766,691
Participant contributions at beginning of year	2011-12-31	$10,784,098
Assets. Other investments not covered elsewhere at end of year	2011-12-31	$2,446,404
Assets. Other investments not covered elsewhere at beginning of year	2011-12-31	$2,191,938
Income. Received or receivable in cash from other sources (including rollovers)	2011-12-31	$383,494
Other income not declared elsewhere	2011-12-31	$1,398,860
Administrative expenses (other) incurred	2011-12-31	$566,871
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2011-12-31	No
Value of net income/loss	2011-12-31	$-8,431,647
Value of net assets at end of year (total assets less liabilities)	2011-12-31	$658,064,911
Value of net assets at beginning of year (total assets less liabilities)	2011-12-31	$664,616,508
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2011-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2011-12-31	No
Were any leases to which the plan was party in default or uncollectible	2011-12-31	No
Investment advisory and management fees	2011-12-31	$49,028
Value of interest in registered invesment companies (eg mutual funds) at end of year	2011-12-31	$228,361,384
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2011-12-31	$333,733,884
Interest on participant loans	2011-12-31	$515,154
Income. Interest from corporate debt instruments	2011-12-31	$69,356
Value of interest in common/collective trusts at end of year	2011-12-31	$319,047,680
Value of interest in common/collective trusts at beginning of year	2011-12-31	$230,345,047
Asset value of US Government securities at end of year	2011-12-31	$1,504,581
Asset value of US Government securities at beginning of year	2011-12-31	$1,644,010
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2011-12-31	$-17,469,525
Net investment gain or loss from common/collective trusts	2011-12-31	$-1,727,680
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2011-12-31	No
Was there a failure to transmit to the plan any participant contributions	2011-12-31	No
Has the plan failed to provide any benefit when due under the plan	2011-12-31	No
Assets. Invements in employer securities at end of year	2011-12-31	$95,938,171
Assets. Invements in employer securities at beginning of year	2011-12-31	$85,917,531
Contributions received in cash from employer	2011-12-31	$18,632,245
Income. Dividends from common stock	2011-12-31	$3,785,196
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2011-12-31	$64,614,560
Did the plan have assets held for investment	2011-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2011-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2011-12-31	No
Aggregate proceeds on sale of assets	2011-12-31	$4,597,984
Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d)	2011-12-31	No
Opinion of an independent qualified public accountant for this plan	2011-12-31	Unqualified
Accountancy firm name	2011-12-31	DELOITTE & TOUCHE LLP
Accountancy firm EIN	2011-12-31	393891517
2010 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2010 401k financial data
Unrealized appreciation/depreciation of other (non real estate) assets	2010-12-31	$13,174,168
Total unrealized appreciation/depreciation of assets	2010-12-31	$13,174,168
Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2010-12-31	$0
Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities)	2010-12-31	$0
Total income from all sources (including contributions)	2010-12-31	$125,625,471
Total loss/gain on sale of assets	2010-12-31	$2,960,806
Total of all expenses incurred	2010-12-31	$42,891,472
Benefit payments and payments to participlants,beneficiaries,insurance carriers and others	2010-12-31	$42,245,307
Expenses. Certain deemed distributions of participant loans	2010-12-31	$26,840
Value of total corrective distributions	2010-12-31	$20,697
Total contributions o plan (from employers,participants, others, non cash contrinutions)	2010-12-31	$45,751,674
Value of total assets at end of year	2010-12-31	$664,616,508
Value of total assets at beginning of year	2010-12-31	$581,882,509
Total of administrative expenses incurred including professional, contract, advisory and management fees	2010-12-31	$598,628
Total interest from all sources	2010-12-31	$653,252
Total dividends received (eg from common stock, registered investment company shares)	2010-12-31	$11,760,846
Has a resolution to terminate the plan been adopted during the plan year or any prior plan year	2010-12-31	No
Total dividends received from registered investment company shares (eg mutual funds)	2010-12-31	$7,868,810
Was this plan covered by a fidelity bond	2010-12-31	Yes
Value of fidelity bond cover	2010-12-31	$10,000,000
If this is an individual account plan, was there a blackout period	2010-12-31	No
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2010-12-31	$0
Were there any nonexempt tranactions with any party-in-interest	2010-12-31	No
Contributions received from participants	2010-12-31	$27,302,549
Participant contributions at end of year	2010-12-31	$10,784,098
Participant contributions at beginning of year	2010-12-31	$9,579,342
Assets. Other investments not covered elsewhere at end of year	2010-12-31	$2,191,938
Assets. Other investments not covered elsewhere at beginning of year	2010-12-31	$1,489,833
Income. Received or receivable in cash from other sources (including rollovers)	2010-12-31	$426,628
Other income not declared elsewhere	2010-12-31	$1,618,476
Administrative expenses (other) incurred	2010-12-31	$205,837
Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser	2010-12-31	No
Value of net income/loss	2010-12-31	$82,733,999
Value of net assets at end of year (total assets less liabilities)	2010-12-31	$664,616,508
Value of net assets at beginning of year (total assets less liabilities)	2010-12-31	$581,882,509
Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond)	2010-12-31	No
Were any loans by the plan or fixed income obligations due to the plan in default	2010-12-31	No
Were any leases to which the plan was party in default or uncollectible	2010-12-31	No
Investment advisory and management fees	2010-12-31	$392,791
Value of interest in registered invesment companies (eg mutual funds) at end of year	2010-12-31	$333,733,884
Value of interest in registered invesment companies (eg mutual funds) at beginning of year	2010-12-31	$292,884,426
Interest on participant loans	2010-12-31	$561,543
Income. Interest from US Government securities	2010-12-31	$32,189
Income. Interest from corporate debt instruments	2010-12-31	$59,520
Value of interest in common/collective trusts at end of year	2010-12-31	$230,345,047
Value of interest in common/collective trusts at beginning of year	2010-12-31	$196,776,861
Asset value of US Government securities at end of year	2010-12-31	$1,644,010
Asset value of US Government securities at beginning of year	2010-12-31	$2,306,801
Net investment gain/loss from registered investment companies (e.g. mutual funds)	2010-12-31	$27,945,836
Net investment gain or loss from common/collective trusts	2010-12-31	$21,760,413
Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets	2010-12-31	No
Was there a failure to transmit to the plan any participant contributions	2010-12-31	No
Has the plan failed to provide any benefit when due under the plan	2010-12-31	No
Assets. Invements in employer securities at end of year	2010-12-31	$85,917,531
Assets. Invements in employer securities at beginning of year	2010-12-31	$78,845,246
Contributions received in cash from employer	2010-12-31	$18,022,497
Income. Dividends from common stock	2010-12-31	$3,892,036
Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers	2010-12-31	$42,245,307
Asset. Corporate debt instrument debt (other) at beginning of year	2010-12-31	$0
Did the plan have assets held for investment	2010-12-31	Yes
Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser	2010-12-31	No
Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC	2010-12-31	No
Aggregate proceeds on sale of assets	2010-12-31	$2,960,806
Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d)	2010-12-31	No
Opinion of an independent qualified public accountant for this plan	2010-12-31	Unqualified
Accountancy firm name	2010-12-31	DELOITTE & TOUCHE, LLP
Accountancy firm EIN	2010-12-31	133891517
2009 : ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2009 401k financial data
Total value of distributions paid in property other than in cash, annuity contracts, or publicly traded employer securities	2009-12-31	$0

Form 5500 Responses for ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN

2022: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2022 form 5500 responses
2022-01-01	Type of plan entity	Single employer plan
2022-01-01	Submission has been amended	No
2022-01-01	This submission is the final filing	No
2022-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2022-01-01	Plan is a collectively bargained plan	Yes
2022-01-01	Plan funding arrangement – Trust	Yes
2022-01-01	Plan benefit arrangement - Trust	Yes
2021: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2021 form 5500 responses
2021-01-01	Type of plan entity	Single employer plan
2021-01-01	Submission has been amended	No
2021-01-01	This submission is the final filing	No
2021-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2021-01-01	Plan is a collectively bargained plan	Yes
2021-01-01	Plan funding arrangement – Trust	Yes
2021-01-01	Plan benefit arrangement - Trust	Yes
2020: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2020 form 5500 responses
2020-01-01	Type of plan entity	Single employer plan
2020-01-01	Submission has been amended	No
2020-01-01	This submission is the final filing	No
2020-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2020-01-01	Plan is a collectively bargained plan	Yes
2020-01-01	Plan funding arrangement – Trust	Yes
2020-01-01	Plan benefit arrangement - Trust	Yes
2019: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2019 form 5500 responses
2019-01-01	Type of plan entity	Single employer plan
2019-01-01	Submission has been amended	No
2019-01-01	This submission is the final filing	No
2019-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2019-01-01	Plan is a collectively bargained plan	Yes
2019-01-01	Plan funding arrangement – Trust	Yes
2019-01-01	Plan benefit arrangement - Trust	Yes
2018: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2018 form 5500 responses
2018-01-01	Type of plan entity	Single employer plan
2018-01-01	Submission has been amended	No
2018-01-01	This submission is the final filing	No
2018-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2018-01-01	Plan is a collectively bargained plan	Yes
2018-01-01	Plan funding arrangement – Trust	Yes
2018-01-01	Plan benefit arrangement - Trust	Yes
2017: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2017 form 5500 responses
2017-01-01	Type of plan entity	Single employer plan
2017-01-01	Submission has been amended	No
2017-01-01	This submission is the final filing	No
2017-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2017-01-01	Plan is a collectively bargained plan	Yes
2017-01-01	Plan funding arrangement – Trust	Yes
2017-01-01	Plan benefit arrangement - Trust	Yes
2016: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2016 form 5500 responses
2016-01-01	Type of plan entity	Single employer plan
2016-01-01	Submission has been amended	No
2016-01-01	This submission is the final filing	No
2016-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2016-01-01	Plan is a collectively bargained plan	Yes
2016-01-01	Plan funding arrangement – Trust	Yes
2016-01-01	Plan benefit arrangement - Trust	Yes
2015: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2015 form 5500 responses
2015-01-01	Type of plan entity	Single employer plan
2015-01-01	Submission has been amended	No
2015-01-01	This submission is the final filing	No
2015-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2015-01-01	Plan is a collectively bargained plan	Yes
2015-01-01	Plan funding arrangement – Trust	Yes
2015-01-01	Plan benefit arrangement - Trust	Yes
2014: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2014 form 5500 responses
2014-01-01	Type of plan entity	Single employer plan
2014-01-01	Submission has been amended	No
2014-01-01	This submission is the final filing	No
2014-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2014-01-01	Plan is a collectively bargained plan	Yes
2014-01-01	Plan funding arrangement – Trust	Yes
2014-01-01	Plan benefit arrangement - Trust	Yes
2013: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2013 form 5500 responses
2013-01-01	Type of plan entity	Single employer plan
2013-01-01	Submission has been amended	No
2013-01-01	This submission is the final filing	No
2013-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2013-01-01	Plan is a collectively bargained plan	Yes
2013-01-01	Plan funding arrangement – Trust	Yes
2013-01-01	Plan benefit arrangement - Trust	Yes
2012: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2012 form 5500 responses
2012-01-01	Type of plan entity	Single employer plan
2012-01-01	Submission has been amended	No
2012-01-01	This submission is the final filing	No
2012-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2012-01-01	Plan is a collectively bargained plan	Yes
2012-01-01	Plan funding arrangement – Trust	Yes
2012-01-01	Plan benefit arrangement - Trust	Yes
2011: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2011 form 5500 responses
2011-01-01	Type of plan entity	Single employer plan
2011-01-01	Submission has been amended	No
2011-01-01	This submission is the final filing	No
2011-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2011-01-01	Plan is a collectively bargained plan	Yes
2011-01-01	Plan funding arrangement – Trust	Yes
2011-01-01	Plan benefit arrangement - Trust	Yes
2009: ALLIANT ENERGY CORPORATION 401(K) SAVINGS PLAN 2009 form 5500 responses
2009-01-01	Type of plan entity	Single employer plan
2009-01-01	Submission has been amended	No
2009-01-01	This submission is the final filing	No
2009-01-01	This return/report is a short plan year return/report (less than 12 months)	No
2009-01-01	Plan is a collectively bargained plan	Yes
2009-01-01	Plan funding arrangement – Trust	Yes
2009-01-01	Plan benefit arrangement - Trust	Yes

Potentially related plans

ALLIANT ENERGY SEVERANCE PLAN [EIN = 391380265]

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Company Name:	ALLIANT ENERGY CORPORATE SERVICES, INC.
Employer identification number (EIN):	391914946
NAIC Classification:	221100

Jurisdiction of Incorporation:	Iowa Secretary of State Business Entities
Incorporation Date:	1997-12-08
Company Identification Number:	212193
Legal Registered Office Address:	505 5TH AVE STE 729 DES MOINES United States of America (USA) 50309