401(k) · DOL Form 5500 · 2022

Aon Corporation 401(k) Plan

Data updated 2026-08-06

$5.4B
Total assets
12,608
Participants
100th
Percentile by assets
$429,847
Avg per participant
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Official DOL plan name: Aon Savings Plan · Sponsored by Aon Corporation · Illinois · Finance & Insurance

$5.4B in assets, 12,608 participants

Aon Corporation's Aon Savings Plan reported $5.4B in total assets and 12,608 participants in its 2022 DOL Form 5500 filing, ranking in the 100th 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.

  • 100th percentile by assets (of 139,258 plans)
  • #9,229 in Finance & Insurance (9,267 peers)

Coverage in Illinois

Aon Savings Plan covers 12,608 participants in Illinois, 16x the typical Illinois plan (state average ~768 per filing). Assets: $5.4B.

$5.4B
total plan assets (2022 EOY)
12,608
covered participants
100th
percentile by assets (of 139,258 plans)
$429,847
avg assets per participant

The plan reported a net loss of $1.2B for the year, a single-year figure driven by markets and benefit payments, not a measure of plan health.

State

Participants vs Illinois filers

In Illinois, the average filing covers about 768 participants across 5,440 plans. Aon Savings Plan reports 12,608 participants - 16x that state average ($5.4B EOY assets).

Illinois filing particulars

Total Assets (Beginning of Year)$6.5B
Net Assets (End of Year)$5.3B
Net Income-$1.2B
Employer EIN363051915
Plan Effective Date1984-07-01
Filing StatusFILING RECEIVED

Sponsor Plan History (Aon Corporation)

$6.5B$7B$7.5B$8B$8.5B 202220232024 $6.93B $8.17B ▲ +17.9%
Total plan assets by year, all Aon Corporation plans on file
Year Plans Participants Total Assets
2022 3 14,536 $6.9B
2023 2 15,754 $7.8B
2024 2 15,620 $8.2B

Nearby 401(k) Plans in Illinois

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

Aon Savings Plan vs. nearby 401(k) plans in Illinois, assets vs. participants

Aon Savings Plan vs. nearby 401(k) plans in Illinois, assets vs. participants Scatter plot of 6 data points. 050000100000150000200000250000 05101520 Total assets ($B) Participants Aon Savings PlanState Farm 401(k) Sa…Accenture United Sta…Abbott Laboratories …United Airlines Pilo…Walgreens Retirement…
Aon Savings Plan vs. nearby 401(k) plans in Illinois, assets vs. participants

Scale composition for Aon Savings Plan

Aon Savings Plan reports $5.4B in end-of-year assets across 12,608 participants (0.047% of the $11.6T held by all Form 5500 filers in the national rollup , and 0.014% of 89,805,449 covered participants) - about $429,847 per participant (3.1x the national average assets-per-participant) . Net income for plan year 2022 was -$1.2B.

This plan identity (EIN 363051915, plan #020) has 3 Form 5500 filings on file from 2022 to 2024 , with end-of-year assets moving from $5.4B to $6.7B (+23.7%) while covered participants moved from 12,608 to 13,974 . Single-year sparse filers cannot show that trail.

Plan year Participants EOY assets Filing
2022 12,608 $5.4B This page
2023 13,948 $6.2B Open filing
2024 · index core 13,974 $6.7B Open filing

The same sponsor also keeps 2 other index-core plans on PlainRetire:

Similar-Sized 401(k) Plans Nationally

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

Frequently Asked Questions

How did Aon Savings Plan assets move in 2022?
Aon Savings Plan declined sharply - down 17.0% during 2022, from $6.5B to $5.4B. Reported net income was -$1.2B.
How have Aon Corporation plan assets changed over time?
Across 3 plan years on file (2022-2024), Aon Corporation's sponsor-wide assets grew 17.9%, from $6.9B to $8.2B.
Where does Aon Savings Plan rank by assets among Form 5500 filers?
Aon Savings Plan ranks in the 100th 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 Aon Savings Plan?
Among 401(k) plans in other states, the closest by assets is Nextera Energy, Inc. Employee Retirement Savings Plan in FL ($5.4B, 14,889 participants).

Filing takeaways

Ways to act on Aon Savings Plan's numbers.