If you sponsor an employer retirement plan, Form 5500 is one of your most visible compliance obligations. Filed annually with the Department of Labor, this form serves as a window into your plan’s financial condition, operations, and participant data. The problem? Many plan sponsors unknowingly submit inaccurate or incomplete filings — and the penalties for errors can be significant. Understanding the most common mistakes is the first step toward avoiding them.
Missing or Incorrect Participant Counts
One of the most frequent errors involves participant counting — and it matters more than most sponsors realize. The number of participants you report determines which schedules you must attach, whether your plan requires an independent audit, and which filing category applies to your plan. A common mistake is counting only active employees while overlooking former employees with vested balances still in the plan, or employees who are eligible to participate but have not yet enrolled.
Review your plan document’s eligibility definition carefully and reconcile it against your recordkeeper’s data each year. Small discrepancies in participant counts can trigger the wrong filing category — potentially requiring an audit you weren’t prepared for, or conversely, skipping one you were required to complete.
Late Filings and Missed Deadlines
Form 5500 is generally due by the last day of the seventh month following the close of the plan year. For calendar-year plans, that’s July 31. A 2½-month extension is available by filing Form 5558 before the original due date — but this step is often overlooked or forgotten entirely.
The DOL’s penalty for late filing can reach $250 per day, with a maximum of $150,000 per filing. The IRS imposes its own separate penalties on top of that. The good news: the DOL’s Delinquent Filer Voluntary Correction Program (DFVCP) allows late filers to come into compliance at significantly reduced penalty rates. If you’ve missed a deadline, acting proactively is far better than waiting to be discovered.
Schedule and Attachment Errors
Form 5500 is not a standalone document. Depending on your plan type and size, it requires specific schedules — and submitting the wrong ones, or omitting required ones, is surprisingly common. Frequent issues include:
- Failing to attach Schedule A when the plan includes insurance contracts
- Omitting Schedule C when reportable compensation was paid to service providers
- Incorrectly completing Schedule H or Schedule I based on plan size
- Missing the independent auditor’s report for large plans when one is required
These aren’t minor technical oversights. Missing or incomplete schedules can result in the filing being rejected or flagged for review. Work through a checklist annually with your plan’s recordkeeper, TPA, and ERISA counsel to confirm every required attachment is in order before you submit.
Plan Document and Operational Inconsistencies
The information you report on Form 5500 must align with how your plan actually operates — and with what your plan document says. One underappreciated mistake is reporting plan features that don’t match actual practice. For example, if your plan document allows loans but the plan has never implemented a loan policy, that discrepancy can create problems during an audit.
Similarly, errors in reporting plan assets, investment options, or prohibited transactions can draw unwanted scrutiny. Your Form 5500 data should be reconciled against trust statements and recordkeeper reports before the filing is submitted — not after the fact.
Key Takeaway
Form 5500 filing mistakes are common, but they are also largely preventable. Build a consistent annual process that includes early coordination between your recordkeeper, third-party administrator, and ERISA counsel. Confirm participant counts, verify the correct schedules, meet your deadlines, and reconcile plan data before filing. As a plan fiduciary, you are ultimately responsible for the accuracy of this filing — and getting it right protects both your plan participants and your organization.
This article is for informational purposes only and does not constitute legal, tax, or investment advice. Readers should consult with their qualified financial, legal, and tax professionals before making any financial or business decisions.
About the Author: Allen Bronton, AIF®, PPC®, is the founder of Clear Financial Strategies and author of ERISA Fiduciary Responsibility: The Good, the Bad, and the Ugly. Allen has been recognized as a ★ 2026 Five Star Wealth Manager — Five Star Professional in both Chicago, IL and Jacksonville, FL. The 2026 Five Star Wealth Manager award is based on 10 objective eligibility and evaluation criteria, including client retention rates, client assets administered, and a favorable regulatory history. Advisors do not pay a fee to be considered or placed on the final list, although they may choose to purchase advertising packages after being selected. The rating is not indicative of future performance or success and should not be construed as an endorsement by any client or by Five Star Professional. More information about the selection criteria is available at www.fivestarprofessional.com.
