401(k) · DOL Form 5500 · 2022

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

Data updated 2026-08-06

$1.2B
Total assets
3,263
Participants
99th
Percentile by assets
$357,352
Avg per participant
PlainRetire home → About this data

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.

  • 99th percentile by assets (of 139,258 plans)
  • #671 in Utilities (739 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 ~565 per filing). Assets: $1.2B.

$1.2B
total plan assets (2022 EOY)
3,263
covered participants
99th
percentile by assets (of 139,258 plans)
$357,352
avg assets per participant

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.

State
Industry

Participants vs Wisconsin filers

In Wisconsin, the average filing covers about 565 participants across 2,767 plans. Alliant Energy Corporation 401(k) Savings Plan reports 3,263 participants - 5.8x that state average ($1.2B EOY assets).

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.)

$1.3B$1.4B$1.5B$1.6B$1.7B 202220232024 $1.4B $1.63B ▲ +16.4%
Total plan assets by year, all Alliant Energy Corporate Services, Inc. plans on file
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

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 Corpo…Johnson Controls Ret…Fiserv 401(k) Saving…Kimberly-Clark Corpo…Rockwell Automation …Nm Employee Savings …
Alliant Energy Corporation 401(k) Savings Plan vs. nearby 401(k) plans in Wisconsin, assets vs. participants

Similar-Sized 401(k) Plans Nationally

401(k) plans in other states closest to Alliant Energy Corporation 401(k) Savings Plan by total assets, not by location.

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 139,258 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).

Next read for Alliant Energy Corporation 401(k) Saving…

Filing takeaways

Ways to act on Alliant Energy Corporation 401(k) Savings Plan's numbers.

  • By total assets, Alliant Energy Corporation 401(k) Savings Plan ranks among the largest 1% of all filed plans. See the largest plans
  • Compare it side-by-side against 3 similar 401(k) plans in Wisconsin. Compare plans
  • Alliant Energy Corporate Services, Inc.'s sponsor-wide assets have grown 17.0% since 2022 across 3 plan years on file. More Utilities plans