Internal Revenue Service (IRS) Edition Rev. January 2025 3 pages

Form 5558 — Application for Extension of Time To File Certain Employee Plan Returns

The IRS form a retirement plan's sponsor or administrator files for a one-time extension of time to file the plan's Form 5500 series return or Form 8955-SSA.

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Form 5558 · Application for Extension of Time To File Certain Employee Plan Returns
The official Internal Revenue Service (IRS) form, edition Rev. January 2025 — blank
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Form 5558 (2025) Application for Extension of Time To File Certain Employee Plan Returns — page 1 of 3
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Form 5558 (2025) Application for Extension of Time To File Certain Employee Plan Returns — page 2 of 3
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Form 5558 (2025) Application for Extension of Time To File Certain Employee Plan Returns — page 3 of 3
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Fill this form online Blank PDF from Internal Revenue Service (IRS)

What is Form 5558?

Form 5558, Application for Extension of Time To File Certain Employee Plan Returns, gives a plan a one-time extension to file its Form 5500, 5500-SF or 5500-EZ annual return/report and/or its Form 8955-SSA. Filed on or before the return's normal due date, a properly completed application is automatically approved to a date no later than the 15th day of the 3rd month after that normal due date.

One Form 5558 covers one plan, and can extend both its Form 5500 series return and its Form 8955-SSA. Since January 1, 2025 it can be filed electronically through EFAST2 or on paper with the IRS, and the form says the January 2025 revision must be used. The IRS doesn't return approved copies.

FileIt asks the handful of questions in plain language, prints them into the IRS's own PDF and keeps it in your vault, next to the plan's Form 5500-EZ if you file one with FileIt.

Who files
The plan sponsor (generally the employer) or plan administrator named on the plan's return.
When
On or before the normal due date of the return being extended.
Extension
Automatic, to no later than the 15th day of the 3rd month after the normal due date.
Where
Electronically through EFAST2, or on paper to Department of the Treasury, Internal Revenue Service Center, Ogden, UT 84201-0045.
Edition
Rev. January 2025
Agency
Internal Revenue Service (IRS), Department of the Treasury

Who needs to fill out Form 5558?

  • Owners of one-participant (solo) 401(k) plans who need more time for Form 5500-EZ.
  • Employers and plan administrators that file Form 5500 or 5500-SF for a retirement or welfare plan.
  • Plans that must file Form 8955-SSA for separated participants with deferred vested benefits.
  • Not needed when the plan year and the employer's tax year are the same and the employer already has an extension for its income tax return past the plan return's due date: that extension applies automatically (the instructions).

When to use Form 5558

  • Before the normal due date of the plan's Form 5500 series return or Form 8955-SSA, when you won't be ready to file on time.
  • Once per plan return: it is a one-time extension.

What you need before you start

  • The name and address of the plan sponsor or plan administrator.
  • The employer's EIN (not a Social Security number).
  • The plan's formal name and three-digit plan number (001, 002 ...).
  • The plan year end date.
  • The extended due date you are asking for, for the Form 5500 series return and/or Form 8955-SSA.

What’s on Form 5558

The 2025 edition has 3 pages. FileIt asks for it in 2 parts:

  1. Part I: IdentificationPlan sponsor or plan administrator
  2. Part II: Extension of time to file Form 5500 series and/or Form 8955-SSAPlan sponsor or plan administrator

How to fill out Form 5558, step by step

1 Part I, A: Name and address

Enter the plan sponsor or plan administrator as listed on the plan's return. For an address outside the United States, enter the city, province or state, and country, with the postal code as that country writes it.

2 Part I, B-E: EIN, plan and plan year

Enter the employer's nine-digit EIN, the plan's formal name, its three-digit plan number, and the plan year end date (MM/DD/YYYY).

3 Part II, line 1: First return

Tick only if the extension on line 2 is for the plan's very first Form 5500 series return/report.

4 Part II, lines 2-3: Extended dates

Enter the date you are asking for: line 2 for Form 5500, 5500-SF or 5500-EZ, line 3 for Form 8955-SSA. It should be no later than the 15th day of the 3rd month after the normal due date.

Common mistakes to avoid

  • Filing after the normal due date: a late Form 5558 isn't automatically approved.
  • Using an older revision. The form says the January 2025 revision must be used.
  • Listing several plans on one form or attaching lists of other plans. Use a separate Form 5558 for each plan.
  • Attaching the Form 5500 series return or Form 8955-SSA to Form 5558.
  • Using a Social Security number instead of the employer's EIN.
  • Expecting it to extend the PBGC Form 1 premium filing: it doesn't.

After you fill it out

File it on time, electronically through EFAST2 or on paper with the IRS at the Ogden address in the instructions. The 2025 revision has no signature line.

Keep proof of the filing date (a private delivery service can give you proof of mailing). The IRS doesn't return approved copies.

File the plan's return by the extended date. FileIt keeps your copy in your vault.

Fill out Form 5558 online with FileIt

  1. Pick the person. Choose someone from People and FileIt fills in their name, date of birth, address and other details it already knows.
  2. Answer plain-language questions. One part of the form at a time, with the official help text beside each question — 10 fields in all. Your answers save as you go.
  3. Check the live preview. Watch your answers land on the real Internal Revenue Service (IRS) form, and let FileIt do any worksheet arithmetic.
  4. Generate the official PDF. FileIt prints your answers into the agency’s own PDF and files it in that person’s folder in your vault.

FileIt fills the form — it never files or submits anything for you. Deliver the finished form to whoever asked for it, the way the form’s instructions say.

Start Form 5558 now — it’s free

Form 5558: frequently asked questions

Can I fill out Form 5558 online?

Yes. FileIt prints your answers into the official IRS PDF for paper filing. Since 2025 you can also file Form 5558 electronically through EFAST2 instead.

How long is the extension?

To no later than the 15th day of the 3rd month after the return's normal due date, if Form 5558 is filed on or before that normal due date and properly completed.

Do I need to sign Form 5558?

The January 2025 revision has no signature line.

Can one Form 5558 cover several plans?

No. Use a separate Form 5558 for each plan. One form can extend both a plan's Form 5500 series return and its Form 8955-SSA.

Does it extend my business's income tax return?

No. Form 5558 is only for the plan's Form 5500 series return and Form 8955-SSA. If your business already has an income tax extension and the plan year matches its tax year, the plan return may be extended automatically without Form 5558.

Official sources

FileIt is not affiliated with or endorsed by Internal Revenue Service (IRS) or any government. This page explains the form in general terms and is not legal, tax or immigration advice. Always read the official instructions, and check that you are using the edition the recipient accepts. Page last reviewed 2026-10-25.

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