Who has to file
Form 5500-EZ is for a one-participant plan: one that covers only the owner, or the owner and spouse, of a business they wholly own, or only partners and their spouses, and provides benefits to no one else. A solo cash balance plan fits that description. Such a plan cannot use the full Form 5500 or Form 5500-SF instead.
No return is needed for a year when the plan's assets, added to the assets of every other one-participant plan the business maintains, are $250,000 or less at the end of the plan year. The exception is the final plan year: a return is always due for the year the plan pays out its last dollar, whatever the balance.
Adding plans together catches many owners out. A Solo 401(k) and a cash balance plan sponsored by the same business count as one total. Once the total passes $250,000, each plan files its own 5500-EZ, including a plan that is under $250,000 by itself.
| End-of-year assets | Return due? |
|---|---|
| Cash balance plan $180,000, no other plan | No |
| Cash balance plan $180,000 and Solo 401(k) $120,000 | Yes, one for each plan |
| Cash balance plan $300,000 | Yes |
| Cash balance plan $40,000, final year, all assets paid out | Yes, marked as the final return |
A cash balance plan funded at six figures a year usually passes $250,000 in its second year, so in practice most owners file from year two onward.
When it is due
The return is due on the last day of the seventh month after the plan year ends. For a 2026 calendar plan year, that is August 2, 2027. There are two ways to get more time:
- Form 5558. Filed by the original due date, it extends the deadline once, by up to 2½ months, to October 15, 2027 for a calendar year. You do not attach it to the return.
- The business's tax extension. The deadline moves automatically to the business's extended tax return due date if the plan year and the business's tax year are the same, the business has an extension to a date later than the normal 5500-EZ due date, and you keep a copy of that extension with the plan's records. A deadline extended this way cannot be extended again with Form 5558.
A plan adopted after the year ended, under the rule that lets a new plan count for the prior year, needs no 5500-EZ for that first, retroactive year, although the actuary still prepares a Schedule SB for it. See cash balance plan deadlines or the deadlines calculator for every date in the year.
How to file
You can file on paper, by mail to the IRS in Ogden, Utah, or electronically through EFAST2, the Department of Labor's filing system. Electronic filing becomes mandatory, for plan years beginning on or after January 1, 2025, only if you must file at least 10 returns of any type in the calendar year, which rarely applies to a solo owner.
The return is signed by the plan administrator or the employer. For a solo plan that is you. Unlike the returns of plans with employees, one-participant plan filings are not published online.
The form reports basic details of the plan and the business, including the business's EIN, a code identifying the plan as a cash balance plan, the plan's assets, contributions and distributions for the year, and any unpaid minimum required contribution.
The actuary's Schedule SB
A defined benefit plan's funding is certified each year on Schedule SB, signed by an enrolled actuary. It shows the valuation, the plan's assets and liabilities, the interest rates used, and the minimum required contribution.
For a plan that files Form 5500-EZ, the Schedule SB is not filed with the return. The instructions say the actuary must still complete and sign it and you must keep it with the plan's records. The annual valuation is required every year, including years when no 5500-EZ is due because assets are under $250,000.
If you file late
The penalty for a late Form 5500-EZ is $250 a day, up to $150,000 for each plan year (IRC 6652(e)). It applies to a return that was required and not filed, so a missed year can become expensive even though the plan itself was run correctly.
The IRS has a penalty relief program for late 5500-EZ filers, set out in Rev. Proc. 2015-32. You file the late returns on paper with Form 14704 and pay a reduced fee instead of the full penalty. The sooner a missed filing is caught, the more options you have.