401(k) Audit Firms in Illinois

Last updated · Source data: plan year 2024 Form 5500 filings

Who audits the most 401(k) plans in Illinois?

Sikich CPA LLC audited 228 Illinois plans in plan year 2024, the most of any firm. Overall, 387 firms audited 3,540 plans sponsored in Illinois; the median audited plan had 397 participants.

Most active in Illinois

Sikich CPA LLC

228Illinois plans audited

Top audit firms for Illinois plans

Top 25 firms shown. Counts are retirement plan filings (401(k), 403(b), profit-sharing, and pension) whose sponsor address is in Illinois.

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

Illinois plan audit market at a glance

Illinois employee benefit plan audits, plan year 2024
MeasureValue
Audited plans sponsored in Illinois3,540
Audit firms with at least one IL engagement387
Median audited plan size (participants)397
Share of all U.S. audited plans4.6%

Choosing an audit firm in Illinois

Engagement volume is the most objective public signal of employee benefit plan audit experience: the Department of Labor’s audit quality study found deficiency rates of 76% among CPAs performing one or two plan audits a year, versus 12% at the largest practices. The table above shows which firms do this work in Illinois at real volume.

Beyond volume, ask candidate firms about AICPA Employee Benefit Plan Audit Quality Center membership, who staffs the fieldwork, experience with your recordkeeper and payroll systems, and whether the fee assumes an ERISA Section 103(a)(3)(C) election. A Illinois address is not required — plan audits are performed remotely under the same national standards — but local presence can simplify scheduling and walkthroughs.