When Do You Have to File Form 5500-EZ for a Solo 401(k)? The $250,000 Rule
A Solo 401(k) is famously low maintenance. No employees, no discrimination testing, no outside administrator looking over your shoulder. Then one day your balance crosses $250,000 and the IRS wants a form you have never heard of. If you are wondering when you have to file Form 5500-EZ for a Solo 401(k), the answer is the July after your plan assets pass $250,000 at year end, and every July after that. Nobody at your brokerage will remind you. The filing is on you, because you are the plan administrator.
That surprises people, because everything else about a Solo 401(k) is do-it-yourself. But the 5500-EZ is the one piece of paperwork the plan hangs on you personally. Miss it and the penalties are not small: the IRS can assess $250 per day, up to $150,000 per unfiled return. A form most owners finish in under an hour carries a five-figure penalty schedule if you ignore it. I have seen smart self-employed people sail past three July deadlines without knowing the form existed.
The two triggers that start the clock
Either one of these means you file:
1. Plan assets exceed $250,000 at the end of the plan year. That is December 31 for nearly everyone. Everything the plan owns counts: cash, mutual funds, ETFs, real estate, promissory notes. A $50,000 brokerage balance plus a $200,000 rental property owned by the plan is $250,000 in plan assets. People with self-directed plans trip on this one, because they think of the brokerage balance as "the account" and forget the property.
2. You terminate the plan. Closing the Solo 401(k) completely, distributing everything or rolling it all into IRAs, requires a final 5500-EZ regardless of the balance. Even a $40,000 plan gets a final filing on the way out.
The filing covers the prior plan year, so there is a lag built in. Cross $250,000 during 2025 and your first filing is due July 31, 2026. And here is the part people miss: once you file once, you file every year going forward, even if the balance dips back under $250,000. There is no un-filing.
| Event | Date | What happens |
|---|---|---|
| Plan assets hit $251,000 | Nov 2025 | Trigger met; nothing due yet |
| Plan year ends | Dec 31, 2025 | Assets still over $250,000: filing required |
| First 5500-EZ due | Jul 31, 2026 | File for plan year 2025 |
| Balance falls to $230,000 | 2027 | You still file every year |
The deadline, the extension, and how to actually file
The deadline is the last day of the seventh month after the plan year ends. For a calendar-year plan, that is July 31. If you need more time, file Form 5558 by July 31 to request an extension. Note the order: the extension form is due on the same day the return is due, so you cannot discover the deadline on August 2 and then ask for more time.
Filing itself is straightforward. Paper filers mail the form to the IRS in Ogden, Utah. Electronic filing goes through the Department of Labor's EFAST2 system, and it is mandatory if you file 10 or more returns of any type in the calendar year, including 1099s and W-2s. One newer line worth knowing: the form asks for your plan provider's IRS opinion letter date, so have that on hand before you sit down to fill it out. Your provider can supply it.
My practical advice: put a recurring July 1 reminder on your calendar, and check your December 31 balance every year. If you are anywhere near the line, file. Filing when you turn out not to be required costs you an hour. Not filing when you were required costs you $250 a day.
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Run your own numbers with the free calculatorFrequently asked questions
What happens if I never filed Form 5500-EZ and should have?
File now. The IRS runs a late filer penalty relief program that can reduce the penalty far below the $250-per-day statutory amount, but you have to come forward and file the missing returns. Every additional day of delay is the expensive kind. A CPA who handles retirement plans can usually sort this out in one engagement.
Does a SEP IRA require Form 5500-EZ?
No. SEP IRAs, SIMPLE IRAs, and traditional and Roth IRAs are all exempt from 5500 filing. The 5500-EZ is for one-participant 401(k) plans, money purchase plans, and similar employer plans. This is a genuine administrative edge for the SEP.
Do I file 5500-EZ if I move my Solo 401(k) to a new provider?
If you keep the same trust and tax ID number and are just changing providers, you generally do not owe a filing for the move itself. If you terminate the plan entirely and distribute or roll everything out, you owe a final filing. Confirm with your plan document provider before you assume either way.
Can I e-file Form 5500-EZ?
Yes, through the DOL's EFAST2 system. E-filing is required if you file 10 or more returns of any type during the calendar year, which includes 1099s and W-2s your business issues. Paper filing by mail to Ogden, Utah remains allowed below that threshold.
What counts toward the $250,000 in plan assets?
Everything the plan owns at fair market value on December 31: cash, stocks, bonds, mutual funds, real estate, notes receivable. If you hold property in a self-directed Solo 401(k), get a defensible valuation each year end. The IRS does not accept "I didn't count the house."
Related: Solo 401(k) Setup Deadline: Why December 31 Is the Date That Matters · Can I Contribute to Both a Solo 401(k) and a SEP IRA in the Same Year? · Solo 401(k) Catch-Up Contributions After 50: The $8,000 a SEP IRA Can't Match · Can You Borrow From a Solo 401(k)? Loan Rules, Limits, and the Catch
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