What Is Form 5558? A Complete Guide to Employee Benefit Plan Extensions

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If you sponsor a retirement plan for your business, you may be familiar with the Form 5500 Series, the annual returns used by the IRS and the Department of Labor (DOL) to collect information about employee benefit plans. When additional time is needed to complete an eligible return, Form 5558 may be used to request an extension.

However, not every retirement arrangement has a Form 5500 filing requirement. SEP IRAs, SIMPLE IRAs, and one-participant 401(k) plans follow different reporting rules. Understanding where your plan fits can help you avoid unnecessary filings and potential late-filing penalties.

What Is Form 5558?

Form 5558, the Application for Extension of Time To File Certain Employee Plan Returns, is used to request a one-time extension for:

• Form 5500: Annual Return/Report of Employee Benefit Plan
• Form 5500-SF: Short Form Annual Return/Report of Small Employee Benefit Plan
• Form 5500-EZ: Annual Return of a One-Participant Retirement Plan or Foreign Plan
• Form 8955-SSA: Annual Registration Statement Identifying Separated Participants With Deferred Vested Benefits

When Form 5558 is properly completed and filed by the return’s normal due date, the extension is automatically approved. The extended deadline cannot be later than the 15th day of the third month following the original due date, which generally provides up to 2.5 additional months. No explanation or separate approval request is required.

Does My Plan Need To File Form 5500 in the First Place?

Before filing Form 5558, confirm the plan actually has a Form 5500 or 8955-SSA filing requirement in the first place.

Plans generally exempt:

• SEP IRA: Employers usually skip Form 5500 entirely. The financial institution holding the accounts handles most of the reporting.
• SIMPLE IRA: No annual Form 5500 is generally required. Don’t confuse this with a SIMPLE 401(k), which is a qualified plan and does have a filing requirement.

Plans that may need to file:

• One-participant (Solo) 401(k): Filing Form 5500-EZ generally kicks in once combined plan assets exceed $250,000 at year-end. A final 5500-EZ is required when the plan terminates and distributes all assets, even under that threshold.
• Employer-sponsored plans: Traditional 401(k)s, profit-sharing plans, defined benefit plans, and ESOPs generally file Form 5500 annually.
• Welfare benefit plans: ERISA-covered health and welfare plans often must file, though plans with fewer than 100 participants at the start of the plan year may be exempt if unfunded, fully insured, or some combination, and otherwise qualify. Plans holding assets in trust or certain MEWAs may still have to file regardless of size.

Can Form 5558 Be Filed Electronically?

Yes! Beginning January 1, 2025, Form 5558 can be:

• Filed electronically through ERISA Filing Acceptance System II (EFAST2) using IFILE or approved third-party software.
• Filed on paper with the IRS.

This means filers are no longer limited to printing and mailing Form 5558.

EFAST2 is the electronic filing system used for Form 5500 series returns, Form 5558, and Form PR filings. It’s jointly administered by the DOL, the IRS, and the Pension Benefit Guaranty Corporation (PBGC).

EFAST2 doesn’t send an email confirmation, a downloadable approved copy, or a status lookup after submission. Keep your own filing record from whatever software you use.

When to File 5558?

Form 5500 series returns are generally due on the last day of the seventh month after the plan year ends. For a calendar-year plan, the normal deadline is July 31.

Form 5558 must be filed on or before the return’s normal due date.

A few rules to keep in mind:

• You cannot request an extension after the original deadline has passed.
• If a due date lands on a weekend or legal holiday, filing can generally move to the next business day.

Can I Get an Extension Without Filing Form 5558?

In limited cases, yes. This applies when all of the following are true:

• The plan year matches the employer’s tax year
• The employer already received an extension on its federal tax return
• That extended tax deadline falls later than the normal Form 5500 or 8955-SSA due date

Review the Form 5558 instructions closely before relying on this exception, since it only holds up when all three conditions line up.

How Do I File Form 5558?

Filing Form 5558 comes down to four steps:

1. Confirm the return being extended: Form 5500, 5500-SF, 5500-EZ, or 8955-SSA.
2. Gather plan information: sponsor name, EIN, plan name, three-digit plan number, plan year-end date, and requested extended date.
3. File by the original deadline through EFAST2 or on paper.
4. Retain your filing record, since the IRS doesn’t return an approved copy.

You generally need to file a separate Form 5558 for each plan. If an employer maintains more than one plan, for example a 401(k) plan and a defined benefit plan, a separate Form 5558 is required for each one.

That said, if a single plan needs an extension for both its Form 5500 series return and its Form 8955-SSA, you can use one Form 5558 to cover both. You don’t need to file two.

Keep in mind that Form 5558 only extends your filing deadline. It doesn’t remove the requirement to file the return itself. You’ll still need to submit the Form 5500 series return (and Form 8955-SSA, if applicable) by the extended due date. 

What Happens if Form 5500 Is Filed Late?

Penalties vary by form, plan type, and agency. For 2025 plan-year filings:

• The DOL can assess up to $2,739 per day for a late or incomplete Form 5500.
• The IRS can assess $250 per day, up to $150,000, for certain late employee plan returns.

ERISA-covered plans may reduce DOL penalties through the Delinquent Filer Voluntary Compliance Program if they self-correct before the DOL sends written notice. One-participant plans filing Form 5500-EZ aren’t eligible for DFVC, though separate IRS penalty relief may apply.

E-File Form 5558 Online With TaxBandits

TaxBandits lets you prepare and submit Form 5558 through EFAST2 without printing or mailing anything. It can pull plan details from a previously filed Form 5500 or 5500-SF, cross-check them against DOL records, and flag issues with the plan name, EIN, or plan number before you transmit.