Your Form 5500 Extension Runs Out October 15: Penalties, Form 5558, and the DFVCP Fix

If your company's retirement plan return is not filed by October 15, two federal agencies can fine you at the same time: the IRS at $250 a day, and the Department of Labor at up to $2,739 a day with no maximum. A filing that slips by a single quarter can theoretically cost more than the plan holds for some of your participants. The good news is that the extension itself was easy to get, the filing is straightforward if you start now, and even a missed deadline has a bargain-priced fix. This guide walks through who has to file, what the extension bought you, what happens if October 15 passes, and how to clean up a late return for a fraction of the headline penalty.

Who Has to File a Form 5500​

The Form 5500 series is the annual information return for employee benefit plans covered by ERISA. If your business sponsors a 401(k), a profit-sharing plan, a defined benefit pension, or most employer-provided health and welfare plans, you are probably in the filing population. The most common exemptions are government plans, church plans that have not elected ERISA coverage, and plans maintained solely to comply with workers' compensation or unemployment laws.

Which form you file depends on your plan's size and type:

• Form 5500 (the "long form") is for large plans, generally those with 100 or more participants at the start of the plan year, plus all direct filing entities. Large pension plans generally must attach an audited financial statement from an independent qualified public accountant.
• Form 5500-SF (short form) is for small plans with fewer than 100 participants that meet a handful of conditions, such as holding only easy-to-value assets and not operating as a multiemployer plan.
• Form 5500-EZ is for one-participant plans: a solo 401(k) covering only you, or you and your spouse, with no common-law employees. Unlike the other two, the EZ is filed on paper with the IRS, not through the DOL's electronic system.

The participant count is where small employers most often go wrong. For filing purposes, a participant is generally anyone eligible to participate, not just employees who actually contribute or have an account balance. Every employee who meets the plan's age and service requirements counts, even if they declined to enroll. A company with 60 contributing employees and 50 eligible non-participants has a 100-participant plan and files the long form. The 80-to-120 rule softens the boundary: a plan with between 80 and 120 participants at the start of the year may file in the same category it filed the prior year, so a small plan that creeps to 105 participants can keep filing the short form one more year.

The Deadlines: July 31, Form 5558, October 15​

The Form 5500 is due on the last day of the seventh calendar month after the end of the plan year. For the calendar-year plans most small businesses run, that was July 31, 2026 for the 2025 plan year.

If that date passed without a filing, all is not lost, provided someone filed Form 5558, Application for Extension of Time To File Certain Employee Plan Returns, on or before July 31. A timely Form 5558 grants an automatic extension of up to 2-1/2 months, pushing a calendar-year plan's deadline to October 15. No approval is required and no reason must be given; the extension is yours simply for asking on time. A few mechanics worth knowing:

• One form per plan. If you sponsor both a 401(k) and a separate health and welfare plan that files its own 5500, each plan needs its own Form 5558.
• It covers more than the 5500. The same Form 5558 can also extend Form 8955-SSA, the return reporting separated participants with deferred vested benefits, which shares the 5500's due date.
• Electronic filing is now available. Starting January 1, 2025, Form 5558 can be filed electronically through EFAST2, the DOL's electronic filing system. Paper filing is still accepted at the IRS center in Ogden, Utah, but electronic filing gives you an immediate timestamp, which is exactly the proof you want if the timeliness of your extension is ever questioned.
• The extension extends the filing, not the audit. If your large plan needs an auditor's report, the extra 2-1/2 months are meant for finishing it, not for starting the search for an auditor. Audit season for calendar-year plans runs straight through the extension window, and firms book up.

If no Form 5558 was filed by July 31, there is no extension to enjoy: your return has been late since August 1, and the cleanup program described below is already your best option.

What Happens If October 15 Passes Without a Filing​

Once the extended deadline passes, penalties accrue daily from two directions at once.

The IRS penalty is $250 per day, up to a maximum of $150,000 per plan year. Those are the post-SECURE Act figures; before 2020 the daily rate was $25 with a $15,000 cap, so Congress increased the exposure tenfold and evidently meant it.

The DOL penalty is up to $2,739 per day for penalties assessed after January 15, 2025, and it has no statutory maximum. The DOL adjusts the figure annually for inflation, which is why older articles cite lower numbers like $2,670 or $2,259. At the current rate, a return that is six months late carries a theoretical DOL exposure approaching half a million dollars. The Department rarely assesses the headline maximum against a cooperative small filer, but the number sets the terms of every negotiation, and willful violations can additionally draw criminal penalties.

The damage is not only monetary. A missing 5500 cascades into the Summary Annual Report (SAR), the plain-language summary you must distribute to participants within nine months after the plan year ends, or within two months after the extended 5500 due date when you filed for an extension. For an extended calendar-year plan, that means the SAR is due December 15, and you cannot prepare it until the 5500's numbers are final. Miss October 15 and you are immediately behind on a second deadline with its own penalty structure. Late filings also invite the kind of agency attention nobody wants: the DOL's enforcement program routinely selects plans with missing or defective filings for examination, and an examination triggered by a paperwork failure tends to expand into contribution timing, fee reasonableness, and fiduciary process.

The DFVCP: How to Fix a Late Filing for a Fraction of the Penalty​

Congress and the agencies would rather have your return than your penalty money, so the DOL runs a standing amnesty called the Delinquent Filer Voluntary Compliance Program (DFVCP). The economics are startling compared with the statutory rates:

• The penalty drops to $10 per day per late filing.
• It is capped at $750 per filing for small plans and $2,000 per filing for large plans.
• If you are catching up multiple late years for the same plan at once, a per-plan cap limits the total to $1,500 for small plans and $4,000 for large plans, no matter how many annual reports you file together.
• Participation also brings IRS penalty relief: the IRS will not pursue its own late-filing penalties against a filer that properly completes the DFVCP for the same return.

Eligibility has one decisive condition: you must come forward voluntarily, before the DOL sends you written notice of the failure to file. An IRS late-filer notice does not disqualify you, but a DOL notice does, which is another reason to act in October rather than waiting for the mail to force your hand.

The procedure itself is administrative, not adversarial:

1. File the missing return through EFAST2, checking the DFVCP box on the filing to identify it as a program submission. File every delinquent year you owe, not just the most recent one.
2. Calculate the penalty with the DOL's online calculator and pay it electronically at the time of filing. The calculator applies the caps automatically, so most small-plan sponsors will see exactly $750 per plan.
3. Keep the confirmation. Print the EFAST2 filing receipt and the payment confirmation and store them with the plan's permanent records. If either agency later questions the year, that packet is your complete defense.

One-participant plans need a different door. Form 5500-EZ filers are not eligible for the DFVCP at all. Instead, the IRS offers its own late-filer relief for solo plans: a $500 penalty per late return with a $1,500 per-plan maximum, claimed by marking the late EZ return for the relief program and mailing it to Ogden. If you run a solo 401(k) and your July 31 deadline passed quietly, do not wait for October 15, which was never your extended date unless you filed a 5558. File the EZ under the IRS program now.

A Pre-October 15 Checklist for Plan Sponsors​

With a few weeks left in the extension window, work through these items in order:

1. Confirm the extension exists. Verify that a Form 5558 was actually filed for each plan by July 31, and keep the EFAST2 confirmation or certified-mail receipt where you can find it. An extension you assumed your TPA filed is the most expensive assumption in this process.
2. Lock down your participant count. Pull the eligibility roster as of the first day of the plan year, apply the 80-to-120 rule if you are near the boundary, and confirm whether you are filing the long form, the short form, or the EZ.
3. Chase the auditor's report if you need one. Large-plan audits cannot be rushed in the final week. If your auditor has open items, escalate now.
4. Reconcile before you file, not after. Tie the 5500's contribution, distribution, and asset figures to the trust statements and your payroll records. An amended return filed in November to fix contribution numbers you could have checked in September is a self-inflicted wound.
5. File through EFAST2 and confirm acceptance. Electronic filing is mandatory for the 5500 and 5500-SF, and a submission is not a filing until EFAST2 accepts it. Check the filing status the next business day.
6. Calendar the SAR. Once the 5500 is accepted, prepare the Summary Annual Report and distribute it to participants by December 15. Your TPA can usually generate it from the filed return.
7. Set next year's tripwire. Put two dates on the calendar now: early July to start the return, and July 31 as the hard deadline for both the return and the protective Form 5558. Many sponsors file the 5558 reflexively every year as cheap insurance even when they expect to file on time.

Keep Your Plan Records Organized Year-Round​

Almost every 5500 fire drill traces back to the same root cause: scattered records. The census lives in the payroll system, the trust statements arrive in someone's inbox, the fee disclosures sit in a TPA portal nobody logs into, and every July the sponsor reassembles the puzzle from memory. Plans that keep a single running ledger of contributions, distributions, forfeitures, fee payments, and participant counts can produce the return's numbers in an afternoon instead of a month.

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