Employer · plans filed under one EIN
Aon Corporation
Atlanta, GA · Finance and insurance
Form 5500 information is as filed by the plan administrator with the Department of Labor and may be amended. Figures reflect the plan year shown, not current balances.
Aon Corporation, based in Atlanta, Georgia, sponsors 2 retirement plans with 100 or more participants: 1 defined contribution and 1 defined benefit. Together they reported 38,329 participant records and $8.03B in net assets.
The largest is Aon Savings Plan, a 401(k) plan with 24,731 participants. A person can be counted in more than one plan, so the participant total is a count of records rather than of people.
Employer contributions across the plans were $128M and participant contributions $170M in the latest plan years; benefits paid were $810M. Schedule C compensation reported to service provider organisations totalled $3.4M.
Combined net assets moved from $1.61B in 2009 to $8.03B in 2024 (up 399%). Plan mergers and spin-offs show up here as steps in the series.
Plans
| Plan | Kind | Plan year | Participants | Net assets | Per participant | Employer / active | Sch. C compensation |
|---|---|---|---|---|---|---|---|
| Aon Savings Plan | 401(k) plan | 2024 | 24,731 | $6.59B | $266,398 | $8,152 | $1.6M |
| Aon Retirement Pension Plan | cash balance pension plan | 2024 | 13,598 | $1.44B | $105,696 | $12,388 | $1.8M |
| US median, plan year 2024: DC plans $53,102 per participant, $2,175 employer contribution per active participant; DB plans $86,221 and $10,244. | |||||||
Trend by plan year
| Plan year | Plans | Participant records | Net assets | Employer contributions | Participant contributions |
|---|---|---|---|---|---|
| 2024 | 2 | 38,329 | $8.03B | $128M | $170M |
| 2023 | 2 | 38,862 | $7.64B | $113M | $166M |
| 2022 | 2 | 39,158 | $6.80B | $99.7M | $154M |
| 2021 | 2 | 42,303 | $8.76B | $94.7M | $145M |
| 2020 | 2 | 42,598 | $7.97B | $108M | $136M |
| 2019 | 1 | 24,153 | $5.16B | $90.2M | $136M |
| 2018 | 1 | 27,232 | $4.37B | $90.2M | $135M |
| 2017 | 1 | 28,892 | $4.72B | $99.5M | $157M |
| 2016 | 1 | 40,312 | $5.33B | $135M | $187M |
| 2015 | 1 | 40,533 | $4.88B | $124M | $180M |
| 2014 | 1 | 37,797 | $4.89B | $119M | $172M |
| 2013 | 1 | 36,185 | $4.59B | $114M | $164M |
| 2012 | 1 | 36,352 | $3.79B | $112M | $156M |
| 2011 | 1 | 19,724 | $3.30B | $52.1M | $77.9M |
| 2010 | 1 | 19,174 | $1.77B | $53.2M | $78.3M |
| 2009 | 1 | 20,409 | $1.61B | $51.7M | $77.9M |
History of the plans listed above, in the years each filed the full Form 5500 with 100 or more participants. Plans that have since terminated are not included.
Service providers
| Organisation | Services reported | Plans | Compensation reported |
|---|---|---|---|
| The Northern Trust Co. | Trustee (bank, trust company, or similar financial institution) | 2 | $1,249,061 |
| Alight Solutions | Recordkeeping and information management; Participant communication; Securities brokerage | 1 | $584,100 |
| Legal & General Investment | Investment management | 1 | $383,700 |
| Dodge & Cox | Investment management | 1 | $313,731 |
| The Vanguard Group | Recordkeeping and information management; Consulting (general); Custodial (securities); Securities brokerage | 1 | $308,831 |
| Ernst & Young US LLP | Accounting (including auditing) | 2 | $264,337 |
| Pacific Investment MGT Company | Investment management | 1 | $229,550 |
| Aon Consulting | Actuarial | 1 | $45,813 |
| Pershing LLC | — | 1 | $7,532 |
| State Street Research & MGT Co. | Investment management | 1 | $6,833 |
Organisations paid $5,000 or more by any of these plans, from Schedule C. Individuals are not shown.
Questions and answers
How many retirement plans does Aon Corporation have?
2 plans with 100 or more participants filed Form 5500 under its employer identification number for the latest plan years: Aon Savings Plan and Aon Retirement Pension Plan. Smaller plans and plans filed under a subsidiary's number are not grouped here.
How much does Aon Corporation contribute to its plans?
$128,111,524 in employer contributions across these plans in their latest plan years, about $8,571 per active participant record. Form 5500 reports totals and not the match or accrual formula.
Who provides services to these plans?
Schedule C filings name The Northern Trust Co., Alight Solutions, Legal & General Investment and Dodge & Cox and others. Only organisations paid $5,000 or more by a plan are listed on Schedule C.
Where does this come from?
Form 5500 annual reports filed with the Department of Labor's EFAST2 system, from the EBSA research files, with filings received through 24 Aug 2026. Figures are as filed and may be amended.
Provenance
Source: U.S. Department of Labor, Employee Benefits Security Administration, Form 5500 research files, public domain, with filings received through 24 Aug 2026. Plans are grouped by the sponsor's employer identification number exactly as filed; a company that files under several EINs appears as several employers. See the methodology and corrections.