Running an employer-sponsored retirement plan comes with a year-round set of deadlines, filings, and administrative responsibilities. Missing one can trigger penalties, disqualification risk, or fiduciary liability. Yet many plan sponsors — especially those managing growing businesses — are surprised to learn how much happens between January and December. Understanding the compliance calendar is not just a best practice; it is a core part of your fiduciary duty as a plan sponsor.
First Quarter: Setting the Stage
The year begins with several important tasks that establish the foundation for compliant plan administration. January 31 is typically the deadline to distribute W-2 forms, which must reflect any employee elective deferrals made during the prior year. Plan sponsors should also use early Q1 to confirm that any automatic enrollment or automatic escalation features were applied correctly during the prior year’s enrollment period.
February and March are critical months for initiating compliance testing. Most calendar-year plans must complete nondiscrimination testing — including the Actual Deferral Percentage (ADP) and Actual Contribution Percentage (ACP) tests — to ensure the plan does not disproportionately benefit highly compensated employees. If testing reveals a failure, corrective distributions to affected participants must typically be made by March 15 to avoid a 10% excise tax.
Second Quarter: Participant Notices and Reporting
April brings the Form 5500 filing deadline into focus. While the actual due date for calendar-year plans is July 31, sponsors should begin gathering data well in advance. April 15 is also significant as the deadline to distribute excess contributions to highly compensated employees if corrective action was not completed by March 15 — though this triggers the excise tax.
Spring is also the right time to review and distribute required participant notices if they were not already sent in Q4 of the prior year. These may include:
- Safe harbor notices (if applicable)
- Qualified Default Investment Alternative (QDIA) notices
- Summary Plan Description (SPD) updates
- Automatic enrollment notices
Keeping documentation of each distribution is essential for demonstrating fiduciary compliance.
Third Quarter: Form 5500 and Mid-Year Reviews
July 31 is the Form 5500 filing deadline for calendar-year plans. Plans with 100 or more eligible participants at the beginning of the plan year must attach audited financial statements prepared by an independent qualified public accountant. Missing this deadline without an extension can result in significant IRS and DOL penalties.
If more time is needed, plan sponsors may file Form 5558 before July 31 to extend the deadline to October 15. Use the summer months to conduct a mid-year plan review — confirming that loan repayments are on track, hardship distributions were properly documented, and year-to-date contributions are aligned with participant elections.
Fourth Quarter: Preparing for Year-End
Q4 is arguably the busiest period on the compliance calendar. Key deadlines and action items include:
- October 15: Extended Form 5500 deadline
- November/December: Distribute required annual notices for safe harbor plans, QDIA, and automatic enrollment features — typically at least 30 days before the start of the new plan year
- December 31: Deadline for plan amendments that must be effective for the current plan year, and the deadline to fund certain employer contributions depending on plan design
Year-end is also an ideal time to review the plan document for any needed updates, assess investment lineup performance against benchmarks, and confirm that the plan’s fidelity bond coverage meets DOL requirements — generally covering at least 10% of plan assets.
Key Takeaway
Retirement plan compliance is not a once-a-year event — it is a continuous process with deadlines spread across all twelve months. Plan sponsors who approach the calendar proactively, work closely with their TPA, recordkeeper, and plan advisor, and maintain thorough documentation are far better positioned to avoid costly penalties and fulfill their fiduciary obligations. Consider building an internal compliance calendar that maps each deadline to a responsible party within 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.
