401k Audit Scout — 401(k) Plan Audit Firms Ranked by Form 5500 Filings

401(k) Audit Firms, Ranked by What They Actually File

Every large 401(k) plan must attach an independent CPA’s audit report to its Form 5500. We read every one of those filings and rank the audit firms by real engagement counts — not advertising, not pay-to-play listings.

Last updated September 6, 2026 · Source data: plan year 2024 Form 5500 filings

Who audits the most 401(k) plans in the United States?

Baker Tilly US, LLP signed more audited Form 5500 filings than any other firm in plan year 2024 — 3,776 plans across 51 states and territories. CliftonLarsonAllen LLP and Forvis Mazars, LLP rank second and third. In total, 4,052 firms audited 77,427 employee benefit plans.

77,427Audited plan filings

4,052Audit firms identified

72,776Retirement plan audits

2024Plan year (latest DOL data)

#1 nationally

Baker Tilly US, LLP

3,776audited filings

Clients in 51 states and territories

#2 nationally

CliftonLarsonAllen LLP

3,451audited filings

Clients in 51 states and territories

#3 nationally

Forvis Mazars, LLP

2,687audited filings

Clients in 52 states and territories

Top 25 employee benefit plan audit firms

Largest audit practices by audited Form 5500 filings, plan year 2024
#	Firm	Audited filings	401(k) / retirement plans	States
1	Baker Tilly US, LLP	3,776	3,633	51
2	CliftonLarsonAllen LLP	3,451	3,276	51
3	Forvis Mazars, LLP	2,687	2,583	52
4	CBIZ CPAS P.C.	1,663	1,616	48
5	BDO USA, P.C.	1,288	1,237	45
6	Plante & Moran, PLLC	1,217	1,182	45
7	Eide Bailly LLP	1,204	1,144	42
8	Caron & Bletzer, PLLC	1,138	1,133	41
9	WithumSmith+Brown, PC	1,023	870	39
10	RSM US LLP	984	954	45
11	Crowe LLP	975	930	40
12	Pension Assurance LLP	918	918	42
13	Grant Thornton LLP	816	781	40
14	Wipfli LLP	785	764	42
15	CohnReznick LLP	728	703	35
16	Ernst & Young LLP	629	519	42
17	EisnerAmper LLP	591	580	31
18	PKF O'Connor Davies, LLP	585	577	27
19	Deloitte & Touche LLP	569	455	41
20	Sikich CPA LLC	541	510	33
21	PricewaterhouseCoopers LLP	536	351	29
22	Cherry Bekaert LLP	508	493	28
23	Citrin Cooperman & Company, LLP	502	472	20
24	Miller Kaplan Arase LLP	500	325	17
25	Bonadio & Co., LLP	482	443	22

Audited filings include welfare plans large enough to require an audit; the retirement column counts 401(k)-type and pension plan filings only.

Rankings derived from U.S. Department of Labor Form 5500 filings, plan year 2024. Read the full methodology.

See the full national top 100 →

Each state page ranks the firms auditing plans sponsored in that state, with engagement counts from the same Form 5500 dataset.

How this directory works

Public filings in We download the Department of Labor’s Form 5500 bulk data — every large-plan filing, with the auditor’s name, EIN, and opinion from Schedule H.
Firms assembled Filings are grouped by auditor EIN, so a firm’s count reflects signed audit reports, not marketing claims.
Rankings out National and state tables rank firms by engagement count, with opinion mix and client-size context on every profile.

401(k) Audit Firms, Ranked by What They Actually File

Who audits the most 401(k) plans in the United States?

Top 25 employee benefit plan audit firms

Find 401(k) audit firms by state

How this directory works