Does a Solo 401(k) for You and Your Spouse File 5500-EZ? (w/Examples) + FAQs

This article reflects federal IRS rules as of June 2026 and covers the 2025 plan year (the return filed during the 2026 filing season). Form 5500-EZ is a federal filing only — no state version applies. Tax law changes, so confirm current figures on IRS.gov before you file.

Quick Answer

Yes — a Solo 401(k) covering only you and your spouse files Form 5500-EZ, but only when total plan assets top $250,000 at year-end (or in the plan’s final year). Add both spouses’ balances together for the test. Below $250,000 with no closing, you file nothing for the 2025 plan year.

Most one-participant plan owners assume “solo” means “no paperwork,” and that assumption is the exact spot where penalties begin. A husband-and-wife Solo 401(k) is still treated as a one-participant plan in IRS language, so the same $250,000 reporting line applies to the combined household balance — not to each spouse’s account on its own. Cross that line and skip the form, and the cost is steep.

The stakes are real and time-sensitive. The IRS late-filing penalty for a missed Form 5500-EZ runs $250 per day, capped at $150,000 per plan per year under the SECURE Act, and the standard deadline is July 31 after the plan year ends. Here is what you will learn:

🧮 How to run the $250,000 test correctly when two spouses share one plan
📅 The exact deadline, the Form 5558 extension, and what missing it costs per day
💵 Three fully worked dollar examples showing when you file and when you do not
🛠️ A line-by-line walkthrough of Form 5500-EZ and how to e-file on EFAST2
🛟 The IRS penalty-relief program that caps a late filing at $500–$1,500 instead of six figures

What Form 5500-EZ Actually Is

Form 5500-EZ is the short annual information return for a one-participant retirement plan — the IRS calls it the Annual Return of A One-Participant (Owners/Partners and Their Spouses) Retirement Plan. It is not a tax return, and you owe no tax with it. It simply tells the IRS how much your plan holds, who sponsors it, and whether the plan is still active.

A Solo 401(k) is one type of one-participant plan. The word “one-participant” is the source of most confusion. In plain English, a one-participant plan covers only the business owner (or the owner and one or more business partners) and their spouses — and no common-law employees. So a plan that covers you and your spouse is still a one-participant plan in the eyes of the law, because a spouse does not count as an outside “employee.” That single definition is why a married couple’s Solo 401(k) uses Form 5500-EZ and not the longer, public Form 5500.

The consequence of misreading this is filing the wrong form. If you ever hire a true non-spouse, non-owner employee who becomes eligible, your plan stops being a one-participant plan, and you must switch to the full Form 5500, which carries ERISA Title I duties and public disclosure. A common misconception is that adding a spouse triggers that switch — it does not. Your next step: confirm that the only people covered by your plan are owners, partners, and spouses, and keep a one-line note in your records stating so each year.

The $250,000 Rule for a Husband-and-Wife Plan

The trigger is $250,000 in total plan assets on the last day of the plan year — December 31 for almost everyone. This is the single number that decides whether you file at all. The rule lives in the Form 5500-EZ instructions, and it has not changed for the 2025 plan year.

When two spouses share one Solo 401(k), you aggregate every account in the plan to run the test. That means adding the husband’s pre-tax balance, the wife’s pre-tax balance, both Roth sub-accounts, any voluntary after-tax money, plus the fair market value of any non-cash holdings the plan owns — real estate, promissory notes, or private equity. The test is the plan’s total, not the larger spouse’s account and not “each spouse under $250,000.”

Here is why that matters in dollars. If one spouse holds $180,000 and the other holds $90,000, neither is over $250,000 alone — but the plan holds $270,000, so the plan must file. Missing this is the most common married-couple error. The consequence is a delinquent return exposed to the $250-per-day penalty. Your next step is simple: once a year, on or near December 31, total every sub-account and asset in the plan and write the number down. If it is $250,000 or more, mark July 31 on your calendar.

One more aggregation rule catches people. If you sponsor more than one one-participant plan — say a Solo 401(k) and a separate defined benefit or cash balance plan — you add the balances of all such plans together for the $250,000 test. If the combined total clears $250,000, each plan files its own separate Form 5500-EZ, even if one plan alone is small. The IRS guidance from My Solo 401k Financial flags multiple plans as a frequent trap and an audit red flag.

When You Must File Even Under $250,000

There is one situation where the dollar amount stops mattering: closing the plan. When you terminate a Solo 401(k) and distribute or roll out all the money, you must file a final Form 5500-EZ for the last plan year — regardless of the balance. A $40,000 plan that you close in 2025 still owes a final return.

The reason is that the IRS needs to know the plan is gone and the assets are zero. If you skip the final return, the IRS still shows an open plan with assets and expects future filings — and the missing return can trigger penalty notices years later. The fix is to check the “the final return/report” box in Part I when you wind the plan down, report the ending assets as $0, and file by the normal July 31 deadline for that final year.

A second under-threshold case: a plan that was over $250,000 in a prior year and filed should keep filing in later years even if assets dip, because the IRS expects continuity once a plan starts reporting. When in doubt, filing a return you did not strictly owe causes no harm; not filing one you did owe is what creates penalties.

Which Situation Applies to You?

Tax answers depend on facts. Use this quick branch to find your path, then read the matching section above or below.

Combined plan assets under $250,000 on Dec 31, 2025, and plan still open — You file nothing for 2025. Re-test next December.
Combined plan assets $250,000 or more on Dec 31, 2025 — You file one Form 5500-EZ for the whole plan by July 31, 2026.
You sponsor a Solo 401(k) plus another one-participant plan — Add all balances; if the total clears $250,000, each plan files its own 5500-EZ.
You closed or are closing the plan in 2025 — File a final Form 5500-EZ regardless of balance.
You missed a past required filing — Skip to the penalty-relief section; you likely qualify for the $500-per-return program.
You hired a non-spouse W-2 employee who became eligible — You may have left one-participant status; you likely file the full Form 5500, not the EZ.

Three Worked Examples (Real Dollar Figures)

Numbers make the rule concrete. Each example uses the 2025 plan year, tested on December 31, 2025, and filed during 2026.

Example 1 — Maria and David, just under the line

Maria runs a design studio with a Solo 401(k); her husband David is a participant through the same business. On December 31, 2025, Maria’s account holds $150,000 and David’s holds $85,000. The plan total is $235,000. Because the combined balance is below $250,000 and the plan stays open, they file nothing for the 2025 plan year. Their next step is to re-run the test on December 31, 2026 — a strong market year could push them over, and 2026 contributions plus growth often do exactly that.

Example 2 — The Okafors, pushed over by aggregation

Chidi Okafor has $180,000 in the plan and his wife Ada has $95,000, all as of December 31, 2025. Neither spouse alone tops $250,000, so they assume no filing is needed. But the plan holds $275,000 combined, which clears the line. The Okafors must file one Form 5500-EZ by July 31, 2026 — a single return for the whole plan, not one per spouse. Had they skipped it, the exposure would be $250 per day from August 1, 2026 onward. Their next step is to e-file on EFAST2 before the deadline.

Example 3 — Sam, the late filer who fixes it

Sam, a freelance consultant with a spousal Solo 401(k), crossed $250,000 back on December 31, 2023 and never filed. By mid-2026 he has two delinquent returns (2023 and 2024). Sam has not received a CP 283 penalty notice, so he qualifies for the IRS penalty-relief program. He prepares paper 5500-EZ forms for each missed year, attaches Form 14704, and pays $500 per return — $1,000 total, capped at $1,500 per plan. Without the program, his exposure could have reached $150,000 per year. His saving is enormous, and his next step is mailing the package to the IRS Ogden, UT address.

Deadlines, Extensions, and Timing

The standard due date is July 31 following the close of the plan year. For a calendar-year plan that crossed $250,000 on December 31, 2025, Form 5500-EZ is due July 31, 2026. The form is short, but the deadline is firm, and the per-day penalty clock starts the moment you miss it.

You can buy more time. Filing Form 5558 on or before July 31 grants an automatic 2½-month extension, moving the deadline to October 15, 2026. You must file Form 5558 before the original due date for it to count; a late extension request does nothing. There is no fee for the extension itself.

Timing-wise, the form takes most owners well under an hour once they have the year-end asset total and plan details. Filing electronically is near-instant once your EFAST2 credentials are set up. A common misconception is that an extension to file your personal Form 1040 also extends the 5500-EZ — it does not. The 5500-EZ has its own calendar and its own extension form.

Line-by-Line Walkthrough of Form 5500-EZ

Form 5500-EZ is roughly two pages. You can file electronically through EFAST2 (the Department of Labor’s system) or mail a paper copy to the IRS. E-filing is faster and gives you a confirmation. Here is what each main part asks.

Part I — Annual Return Identification and Status

This top block asks the plan year start and end dates and gives you check boxes for the type of return. Check box A for the first return, box B for an amended return, and “the final return/report” box when you close the plan. There is also a box D used only for the late-filer penalty-relief program. The consequence of checking the wrong box is processing confusion — for a routine on-time filing of an ongoing plan, you leave the special boxes blank.

Part II — Basic Plan Information

Here you enter the plan name, the three-digit plan number (usually 001 for your first plan), the plan’s effective date, and the sponsor’s name, address, and EIN. Use the business’s EIN, not your Social Security number, and not a brand-new EIN each year — consistency lets the IRS match returns across years. Getting the EIN or plan number wrong is a frequent error that makes the IRS think you have a new or different plan.

Financial Information — the assets line

The core financial line reports total plan assets at the beginning and end of the year. For a spousal plan, this is the aggregated figure across both spouses and all sub-accounts and investments. Report fair market value for non-cash assets like real estate or notes. This single number is what the $250,000 test keys on and what the IRS tracks year to year.

Characteristics and Signatures

The form uses plan-characteristic codes (short codes describing the plan type, such as a profit-sharing or money-purchase feature) and a few compliance questions about minimum required distributions and any plan loans. Finally, the plan sponsor signs. The consequence of leaving the signature off is rejection of the filing, which can push you past the deadline — so confirm the signature before you submit.

Mistakes to Avoid

Each of these errors carries a concrete cost.

Testing each spouse separately. You miss the $250,000 line and skip a required return, exposing the plan to $250-per-day penalties.
Forgetting non-cash assets. Leaving out real estate or notes understates plan value, so you wrongly conclude you are under the threshold.
Skipping the final return when you close the plan. The IRS keeps the plan “open” and later issues penalty notices for the missing years.
Using your SSN instead of the business EIN. The IRS cannot match your returns, which can trigger mismatch notices and duplicate-plan confusion.
Assuming a 1040 extension covers the 5500-EZ. It does not; you blow the July 31 deadline and start the penalty clock.
Running multiple Solo 401(k)s without separate filings. Each plan needs its own 5500-EZ once the combined balance clears $250,000, and missing one is an audit flag.
E-filing a delinquent return you meant to fix. Electronically filed late returns are not eligible for the $500 penalty-relief program — those must be mailed on paper.
Waiting for a CP 283 notice before fixing a late filing. Once the IRS sends the penalty notice CP 283, that year is no longer eligible for the relief program.

Common Scenarios at a Glance

The three situations below cover most husband-and-wife Solo 401(k) filers. Each table pairs the situation with the filing result.

Scenario A — Combined balance under the threshold

Plan Situation on Dec 31, 2025	Filing Result for 2025
Spouse 1 has $150,000; Spouse 2 has $80,000; plan total $230,000; plan stays open	No Form 5500-EZ required; re-test next year

Scenario B — Combined balance over the threshold

Plan Situation on Dec 31, 2025	Filing Result for 2025
Spouse 1 has $200,000; Spouse 2 has $90,000; plan total $290,000	One Form 5500-EZ due July 31, 2026, for the whole plan

Scenario C — Plan closed during the year

Plan Situation in 2025	Filing Result for 2025
Couple terminates the plan and rolls out $60,000; balance well under $250,000	Final Form 5500-EZ still required, with the final box checked

The Penalty-Relief Lifeline for Late Filers

If you missed a required filing, you are not stuck with a six-figure penalty. The IRS Penalty Relief Program under Rev. Proc. 2015-32 is built specifically for one-participant plans — owners, partners, and their spouses — exactly the kind of plan a married couple runs.

The cost is small and capped. You pay $500 per delinquent return, up to $1,500 per plan per submission, compared with the standard exposure of up to $150,000 per year. To use it, you prepare a paper Form 5500-EZ for each missing year, write “Delinquent Return Filed under Rev. Proc. 2015-32, Eligible for Penalty Relief” in red at the top of any year that lacks the Box D option, attach Form 14704 as the cover schedule, include a check to the United States Treasury, and mail it to the IRS in Ogden, Utah.

Two hard limits decide eligibility. First, the plan must be a non-ERISA one-participant plan; ERISA-covered plans use the Department of Labor’s Delinquent Filer Voluntary Compliance Program instead. Second, you must act before the IRS sends a CP 283 penalty notice for that year — once that notice arrives, the year drops out of the program. You may alternatively request reasonable cause relief by attaching a signed statement, but if the IRS denies it, the return loses program eligibility and a penalty notice follows.

Pros and Cons of the 5500-EZ Requirement

Understanding the trade-offs helps you stay compliant without over-worrying.

Pros

Simplicity — the EZ is far shorter than the full Form 5500, because one-participant plans skip most ERISA disclosures.
No public disclosure — unlike the full Form 5500, your 5500-EZ data is not posted publicly, protecting your privacy.
No tax due — it is purely informational, so filing it never adds to your tax bill.
Built-in safety net — the penalty-relief program caps late-filing costs at $1,500, which few other IRS programs match.
Clear bright line — the flat $250,000 threshold is easy to test once a year, removing guesswork.

Cons

Easy to overlook — “solo” wrongly signals “no paperwork,” so owners miss the trigger and face penalties.
Harsh base penalty — at $250 per day up to $150,000, the cost of forgetting is severe before relief.
Aggregation complexity — multiple plans and spousal accounts must be combined, which trips up many filers.
Asset-valuation burden — plans holding real estate or notes must value them each year for the assets line.
Separate deadline — the July 31 date is out of sync with personal tax filing, so it is easy to forget.

Do’s and Don’ts

Quick rules to keep your filing clean.

Do’s

Do total every account each December 31 — because the $250,000 test uses the combined plan balance, not per spouse.
Do file by July 31 — because the per-day penalty clock starts the next day.
Do file Form 5558 early if you need time — because a late extension request is invalid.
Do file a final return when you close the plan — because the IRS otherwise treats the plan as still open.
Do keep your EIN and plan number consistent — because it lets the IRS match your returns year to year.

Don’ts

Don’t test each spouse alone — because that misses the combined threshold and skips a required return.
Don’t e-file a delinquent return meant for relief — because the program accepts paper filings only.
Don’t wait for a CP 283 notice — because the year loses penalty-relief eligibility once the notice issues.
Don’t assume your state wants a copy — because the 5500-EZ is a federal-only filing with no state version.
Don’t ignore non-cash assets — because leaving them out can understate the plan below the threshold by mistake.

When to Call a Professional

This article is educational and is not a substitute for advice from a licensed professional about your specific situation. For a straightforward calendar-year spousal Solo 401(k) holding only cash and publicly traded funds, most owners file the 5500-EZ themselves or through their plan provider at no cost.

Bring in a CPA, an ERISA attorney, or your plan provider when the facts get complex: the plan holds real estate or private investments that need annual valuation, you sponsor more than one plan, you have missed one or more required filings, you have hired a non-spouse employee, or you are unwinding the plan. In those cases the professional handles valuation, the penalty-relief paperwork, or the switch to the full Form 5500 — work that costs far less than a missed-filing penalty.

What to Do Next

Follow these steps in order to stay compliant for the 2025 plan year.

Total your plan assets as of December 31, 2025 — add both spouses’ accounts, all sub-accounts, and the fair market value of any non-cash holdings.
Apply the $250,000 test — if the combined total is $250,000 or more (or you closed the plan), you must file.
Gather your details — business EIN, plan number, plan effective date, and beginning- and end-of-year asset totals.
Choose your method — set up EFAST2 credentials to e-file, or prepare the paper form.
File by July 31, 2026 — or submit Form 5558 before that date for an October 15, 2026 extension.
If you are late, act before any CP 283 notice — use the $500-per-return penalty-relief program with Form 14704.

For a deeper form walkthrough, see our companion guide How to Fill Out Form 5500-EZ, and pair this with our articles on Solo 401(k) Contribution Limits, Closing a Solo 401(k), and the pillar guide Solo 401(k) Rules and Reporting.

FAQs

Does a Solo 401(k) with both spouses file one 5500-EZ or two? One. A husband-and-wife Solo 401(k) is a single one-participant plan, so you file one Form 5500-EZ covering the whole plan, not one per spouse. Combine both balances for the $250,000 test for the 2025 plan year.

Do I have to file if my plan is under $250,000? No. For the 2025 plan year, an open one-participant plan with combined assets under $250,000 on December 31, 2025 files no Form 5500-EZ. The one exception is the year you close the plan.

When is Form 5500-EZ due for the 2025 plan year? July 31, 2026. That is the standard deadline for a calendar-year plan. Filing Form 5558 by that date extends it to October 15, 2026, with no fee for the extension.

What is the penalty for filing late? $250 per day, up to $150,000 per plan per year under the SECURE Act. Interest can also apply. Voluntary correction under the IRS relief program caps the cost at $500 per return, up to $1,500.

Do I add both spouses’ accounts for the $250,000 test? Yes. You aggregate every account and asset in the plan, including both spouses’ pre-tax, Roth, and after-tax sub-accounts plus any real estate or notes. The test is the plan total, not each spouse alone.

Do I file a 5500-EZ when I close my Solo 401(k)? Yes. A final Form 5500-EZ is required in the year you terminate the plan, regardless of the balance. Check the final-return box and report the ending assets as zero.

Can I e-file Form 5500-EZ? Yes. You can e-file through the Department of Labor’s EFAST2 system or mail a paper form to the IRS. Note that delinquent returns seeking penalty relief must be filed on paper, not electronically.

Does adding my spouse turn my plan into a regular Form 5500 plan? No. A spouse is not an outside employee, so the plan stays a one-participant plan and keeps using Form 5500-EZ. Hiring a non-spouse eligible employee is what can require the full Form 5500.

Does my state require a separate 5500 filing? No. Form 5500-EZ is a federal IRS filing with no state equivalent. States do not require their own version of this informational return for a Solo 401(k).

I missed several years — am I eligible for penalty relief? Yes, usually. One-participant plans for owners and spouses qualify under Rev. Proc. 2015-32 if you act before a CP 283 notice arrives. You pay $500 per return, capped at $1,500 per plan.

What if I sponsor two one-participant plans? Add them together. You combine the balances of all one-participant plans for the $250,000 test. If the combined total clears the line, each plan files its own separate Form 5500-EZ for the year.

What EIN do I use on the form? Your business EIN. Use the employer’s EIN consistently each year, not your Social Security number and not a new EIN annually, so the IRS can match your returns across plan years.

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