Form 5500 due dates, every plan year end in one table

The rule in one line

Form 5500 is due on the last day of the seventh month after the plan year ends. That is the whole rule for a plan year that runs a full twelve months. Count seven months forward from the month the plan year closed, then go to the end of that month.

Under 29 CFR 2520.104a-5(a)(2), the Form 5500 for a calendar-year plan is due 31 July.

Form 5558 moves that date. File it with the IRS before the statutory date and the return is due later, once, with no further extension after it. The mechanics are on the extension page.

Under the 2025 Instructions for Form 5500, Extension of Time To File Using Form 5558, page 4, a Form 5558 filed on time moves the calendar-year due date to 15 October, an extension of two and a half months.

Every month-end plan year

Most plan years end on the last day of a month. Find yours in the left column. The middle column is the date the return is due with nothing filed. The right column is the date it is due if a Form 5558 went in on time.

Every row is the engine's output for that plan year end, not a date typed into this page. A date marked next year falls in the calendar year after the plan year closed. Where the due date lands on a month end the cell gives the rule rather than a number, because the last day of February is not the same date every year and the cell has to be right in every year. A plan year that ends in February reads off the February row whichever day that month ended on. The clock applies the same rule to any plan year end you give it, including one that is not a month end, and returns the dated answer for the year you enter.

What "seventh month" means when the target month is shorter

Read the 31 July row. Seven months on from July is February, and February has no 31st, so the rule takes you to the last day of the month you land in. The rule says the last day of the seventh month. It does not say the same day number seven months on, which is why you never land on a day that does not exist.

That row is also the reason the middle column gives the rule and not a number. The last day of February is not the same date in every year, so the due date for a 31 July plan year moves with it. Put a year on the row and the engine returns the dated answer for that year. Read the row on its own and the answer is the rule.

The same reading answers a short plan year that ends mid-month. Go seven calendar months forward and take the end of the month you arrive in. Every Form 5500 due date is a month end for that reason, whatever day the plan year closed on.

The cutoff is a time, not a day

Under 29 CFR 2520.104a-2(a) the return is filed electronically through EFAST2, and the Department's EFAST2 guidance says the submission has to reach the system by midnight of the due date.

EFAST2 takes filings around the clock, which makes the due date the last day the return can be accepted rather than the day to start assembling it. A submission that fails validation at eleven at night on the due date is a submission that has not arrived. File the day before and keep the acknowledgment.

Short plan years

A plan that starts mid-year, terminates mid-year, or changes its plan year files a return for a short plan year. The seventh-month rule still applies. It runs from the day the short year ended, not from the day the full year would have ended.

Under the 2025 Instructions for Form 5500, When To File, page 4, a plan year shorter than 12 months is due the last day of the seventh calendar month after the short plan year ends, or by the extended due date.

The trap is a terminating plan. Assets get distributed, the sponsor treats the plan as finished, and nobody notices that the final return came due seven months after the last distribution. That return is the one most often found late in a plan book.

If the date has already passed, two clocks start

Miss the date and one filing carries two separate day counts. They do not start on the same day, and an extension only moves one of them.

For a plan that goes into the Department of Labor's DFVCP, the fee runs from the original due date, without regard to any extension, under 78 FR 6135, Section 3.03(b)(1).

The IRS count is the other way round. Under 26 U.S.C. 6652(e), the section 6652(e) count is determined with regard to any extension of time for filing, so a valid extension moves the day the IRS count starts. So a plan that filed Form 5558, missed the extended date anyway and then used DFVCP pays its program fee from the original date while the IRS counts from the extended one. Most guidance you will read treats the extended date as the start for both. The extension page works through what that costs, and the DFVCP page has the fee schedule.

One plan, worked through

A plan year that has not closed yet, read on the date shown. The engine returns the due date and a countdown, and stops. It prices nothing, because there is nothing late to price.

Why a TPA runs the clock instead of reading the table

The table answers one plan. A TPA holds hundreds, each with its own plan year end, some with a 5558 on file and some without, a few in a short year because of a termination. The clock takes the whole list at once and hands back one register: due date, extended date, and how far past either date each plan sits. That register is the first thing a partner asks for when a client letter arrives, and the plan book that has already run it is the one that answers the same day. If you hold one plan, the tool is free and you are done.