O'Connor & Brooks
Employee benefit plan audit practice profile, built from plan year 2024 Form 5500 filings.
Last updated · Source data: plan year 2024 Form 5500 filings
How many 401(k) plans does O'Connor & Brooks audit?
O'Connor & Brooks was the independent auditor for 3 retirement plan filings in plan year 2024, with clients in 2 states and territories — the #1,843 practice nationally by volume.
Practice at a glance
| Measure | Value |
|---|---|
| Firm EIN (as filed) | 42-1302327 |
| Retirement plan audits (401(k), 403(b), pension) | 3 |
| All audited filings (incl. welfare plans) | 3 |
| States and territories with clients | 2 |
| National rank by retirement plan volume | #1,843 of 3,956 |
| National rank, all audited filings (league-table basis) | #1,807 of 4,052 |
| Average client size (participants) | 309 |
| Largest client (participants) | 435 |
Rankings derived from U.S. Department of Labor Form 5500 filings, plan year 2024. Read the full methodology.
Where does O'Connor & Brooks audit plans?
| State | Plans audited | Share of practice |
|---|---|---|
| Iowa | 2 | 66.7% |
| Illinois | 1 | 33.3% |
Largest concentration: Iowa (2 plans). State reflects the plan sponsor’s address, not the firm’s office locations.
What audit opinions does O'Connor & Brooks issue?
| Opinion type | Filings | Share |
|---|---|---|
| Unmodified (clean) | 3 | 100.0% |
| Qualified | 0 | 0.0% |
| Disclaimer | 0 | 0.0% |
| Adverse | 0 | 0.0% |
As coded on Schedule H. A disclaimer here usually reflects the legacy limited-scope reporting convention (now the ERISA Section 103(a)(3)(C) election), not a failed audit — see the methodology.
Largest plans audited by O'Connor & Brooks
| Plan sponsor | State | Participants |
|---|---|---|
| Mi-T-M Corporation | IA | 435 |
| Mighty M Holdings, Inc. | IA | 356 |
| Signcraft Screenprint, Inc. | IL | 137 |
About this profile
This page is generated from public U.S. Department of Labor Form 5500 filings in which O'Connor & Brooks (EIN 42-1302327) is named as the plan’s independent qualified public accountant. O'Connor & Brooks did not supply, review, or endorse this information, and inclusion is not a recommendation. Filing data can contain sponsor-entered errors; corrections are welcome via the about page.