401(k) · DOL Form 5500 · 2022

Alliant Energy Corporate Services, Inc. 401(k) Plan

Data updated 2026-08-25

$1.2B
Total assets Very large vs avg
3,263
Participants Above avg headcount
99th
Percentile by assets National rank
$357,352
Avg per participant High balance/head
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Official DOL plan name: Alliant Energy Corporation 401(k) Savings Plan · Sponsored by Alliant Energy Corporate Services, Inc. · Wisconsin · Utilities

$1.2B in assets, 3,263 participants

Alliant Energy Corporate Services, Inc.'s Alliant Energy Corporation 401(k) Savings Plan reported $1.2B in total assets and 3,263 participants in its 2022 DOL Form 5500 filing, ranking in the 99th percentile by assets among filed plans. Figures are as reported by the plan sponsor to the Department of Labor, not audited or endorsed by PlainRetire.

  • #670 in Utilities (738 peers)

Coverage in Wisconsin

Alliant Energy Corporation 401(k) Savings Plan covers 3,263 participants in Wisconsin, 5.8x the typical Wisconsin plan (state average ~563 per filing). Assets: $1.2B.

#670
in Utilities (738 peers)
-22.9%
assets change YoY
12×
vs typical plan assets (national mean)

The plan reported a net loss of $347M for the year, a single-year figure driven by markets and benefit payments, not a measure of plan health.

Alliant Energy Corporation 401(k) Savings Plan's outsized position by total assets

Alliant Energy Corporation 401(k) Savings Plan vs every filed plan by assets

End-of-year total assets · plan year 2022 · DOL Form 5500

$1,166,041,158 Top 1% higher than 99% of 139,123 filed plans

This plan $0 $2,050,000,000 every filed plan with reported assets, bucketed by value

Dashed line + filled bar = this entry, among filed plans.

Source U.S. Department of Labor Form 5500 filings (EBSA) · plan year 2022

Alliant Energy Corporation 401(k) Savings Plan's large-plan peer group by participant headcount

Plan-year 2022 Form 5500 filings with a reported participant count, partitioned by headcount band, not by assets. Alliant Energy Corporation 401(k) Savings Plan lands in the large band (3,263 participants).

Plan-year Form 5500 strip

Filing strip 391914946 · Alliant Energy Corporate Services, Inc. PY 2022 · 401(k)

Alliant Energy Corporation 401(k) Savings Plan · $1.2B · 3,263 · 99th

  • SCH $1.2B
  • EBSA 3,263
  • PART 99th
  • TYPE 401(k)
  • NET near Blue Shield of California Tax Deferred Salary Investment Plan
  • BOOK ind #670

Stamps derive from this plan's Form 5500 line items (assets, participants, type, EIN, cohort placement) - not a quality rating of the sponsor. Read with Utilities retirement plans → · Plans in Wisconsin →

Alliant Energy Corporation 401(k) Savings Plan in the asset neighbourhood

Alliant Energy Corporation 401(k) Savings PlanAlliant Energy Corporation 4…$1.2BBlue Shield of California Tax Deferred Salary Investment PlanBlue Shield of California Ta…$1.2BVarian Medical Systems, Inc. Retirement PlanVarian Medical Systems, Inc.…$1.2BUPS/Ipa 401 (K) Savings Plan$1.2BCommercial Metals Companies Retirement PlanCommercial Metals Companies …$1.2B
End-of-year total assets ($B) among Alliant Energy Corporation 401(k) Savings Plan and nearest nationwide 401(k) peers. Source: DOL Form 5500 plan year 2022.

Wisconsin filing particulars

Total Assets (Beginning of Year)$1.5B
Net Assets (End of Year)$1.2B
Net Income-$347M
Employer EIN391914946
Plan Effective Date1983-01-01
Filing StatusFILING RECEIVED

Sponsor Plan History (Alliant Energy Corporate Services, Inc.)

Sponsor-wide plan assets over time

All Alliant Energy Corporate Services, Inc. plans reported in each filing year

Latest sponsor-wide plan assets
$1.6B 16.956327726571477% vs 2022
2024 filing year
$1.3B$1.4B$1.5B$1.6B$1.7B 202220232024 $1.4B $1.63B ▲ +16.4%
Year Plans Participants Total Assets
2022 2 3,712 $1.4B
2023 2 3,484 $1.6B
2024 2 3,621 $1.6B

Nearby 401(k) Plans in Wisconsin

Peer 401(k) plans, same state, same plan type, ranked by total assets.

Alliant Energy Corporation 401(k) Savings Plan vs. nearby 401(k) plans in Wisconsin, assets vs. participants Scatter plot of 6 data points. 0100002000030000 0123456 Total assets ($B) Participants Alliant Energy Corporation 401(k) Savings Plan, Total assets ($B): 1.166041158 · Participants: 3263Alliant Energy Corporation 401(k) Savings PlanJohnson Controls Retirement Savings and Investment Plan, Total assets ($B): 5.548820507 · Participants: 28701Johnson Controls Retirement Savings and Investment PlanFiserv 401(k) Savings Plan, Total assets ($B): 4.339639169 · Participants: 26610Fiserv 401(k) Savings PlanKimberly-Clark Corporation 401(k) & Profit Sharing Plan, Total assets ($B): 3.978902 · Participants: 11034Kimberly-Clark Corporation 401(k) & Profit Sharing PlanRockwell Automation Retirement Savings Plan, Total assets ($B): 3.151693798 · Participants: 8032Rockwell Automation Retirement Savings PlanNm Employee Savings Plan, Total assets ($B): 2.385991887 · Participants: 7423Nm Employee Savings Plan
Alliant Energy Corporation 401(k) Savings Plan vs. nearby 401(k) plans in Wisconsin, assets vs. participants
Compare Alliant Energy Corporation 401(k) Savings Plan side-by-side with 3 peers →

Alliant Energy Corporation 401(k) Savings Plan's out-of-state 401(k) peers by assets and headcount

Outside Wisconsin, the nearest 401(k) by assets is Blue Shield of California Tax Deferred Salary Investment Plan in CA ($1.2B); by covered participants it is Pechanga Development Corporation 401(k) Plan in CA (3,263 participants). Same-state nearby plans are listed separately above.

Closest by plan assets

Nearest other-state filings by tot_assets_eoy ($1.2B here).

Similar participant headcount

Nearest other-state filings by covered participants (3,263 participants); asset peers above are excluded.

DOL Form 5500 plan year 2022. Asset totals can differ widely at the same headcount; neither axis is a quality rating.

Frequently Asked Questions

How did Alliant Energy Corporation 401(k) Savings Plan assets move in 2022? ▼
Alliant Energy Corporation 401(k) Savings Plan declined sharply - down 22.9% during 2022, from $1.5B to $1.2B. Reported net income was -$347M.
How have Alliant Energy Corporate Services, Inc. plan assets changed over time? ▼
Across 3 plan years on file (2022-2024), Alliant Energy Corporate Services, Inc.'s sponsor-wide assets grew 17.0%, from $1.4B to $1.6B.
Where does Alliant Energy Corporation 401(k) Savings Plan rank by assets among Form 5500 filers? ▼
Alliant Energy Corporation 401(k) Savings Plan ranks in the 99th percentile by end-of-year assets among 139,126 plans that reported assets for plan year 2022 (among the largest 1% of all filed plans).
Which 401(k) plans are similar in size to Alliant Energy Corporation 401(k) Savings Plan? ▼
Among 401(k) plans in other states, the closest by assets is Blue Shield of California Tax Deferred Salary Investment Plan in CA ($1.2B, 8,169 participants).
Which 401(k) plans cover a similar participant headcount to Alliant Energy Corporation 401(k) Savings Plan? ▼
Among 401(k) plans in other states, the closest by covered participants is Pechanga Development Corporation 401(k) Plan in CA (3,263 participants, $149M in assets).

Source: U.S. Department of Labor, Employee Benefits Security Administration (EBSA), Form 5500 public disclosure dataset. Plan year 2022.

Source: DOL EFAST2 filing system (efast.dol.gov) - original filing retrieval by EIN 391914946.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from U.S. Department of Labor Form 5500 filings (EBSA). See our methodology for details.