Guides

Solo 401(k) had a non-owner employee: Form 5500-EZ hard stop

A hard-stop guide for Solo 401(k) sponsors who hired a non-owner employee and need to check whether one-participant plan status still applies.

By Yann LephayPublished 2026-06-05 · Last updated 2026-06-05

Summary

Form 5500-EZ is for one-participant plans and certain foreign plans. If the business has a non-owner employee who affects plan eligibility, the filing may no longer be a simple Solo 401(k) packet. Stop before preparing Form 5500-EZ and review the plan rules with official guidance or a professional.

A non-owner employee can break the simple one-participant-plan assumption.

Core questionOne-participant plan statusDo not assume Solo 401(k) status after hiring.
RiskWrong form or plan failureEmployee eligibility can change the compliance picture.
Product boundaryHard stopNo coverage, nondiscrimination or eligibility analysis.

Why this is a hard stop

The product assumes a simple one-participant plan. Hiring a non-owner employee can create eligibility and coverage questions that determine whether the plan is still in the right filing category.

Facts to collect before asking for help

Collect employee hire date, hours, age, service history, ownership relationship, plan eligibility terms, controlled-group facts and any prior plan amendments or notices.

Where the packet stops

Solo 5500 Desk does not decide employee eligibility, coverage testing, controlled-group status or whether another Form 5500 series return is required.

Common questions

Can I use Form 5500-EZ if I hired an employee?

Not automatically. Review whether the plan is still a one-participant plan and whether the employee affects eligibility, coverage or filing obligations.

Does a part-time employee always break Solo 401(k) status?

The answer depends on plan terms, hours, eligibility rules and related-employer facts. That analysis is outside a simple packet workflow.

Can Solo 5500 Desk review employee eligibility?

No. It only supports simple one-participant plan packet preparation. Employee eligibility, controlled group and coverage analysis require official guidance or professional review.

Related guides

Solo 401(k) owner-only eligibility for Form 5500-EZ

The common-law employee question that decides whether a simple one-participant packet is still the right lane.

Do I need to file Form 5500-EZ for my Solo 401(k)?

The direct filing test for one-participant plans: asset threshold, final year, deadline, and filing method.

Solo 401(k) $250,000 threshold for Form 5500-EZ

How the IRS $250,000 one-participant plan asset threshold works for Solo 401(k) Form 5500-EZ filing.

Official sources

IRS Form 5500-EZ filing noticesIRS states the $250,000 asset exception and the last-day-of-the-7th-month deadline. Official source reviewed for this MVP on June 11, 2026.IRS Instructions for Form 5500-EZOfficial instructions explain combined one-participant plan assets, final returns, and electronic filing requirements. Official source reviewed for this MVP on June 11, 2026.IRS one-participant plan project resultsIRS describes common one-participant plan filing mistakes, final-year filings, and failure-to-file penalties. Official source reviewed for this MVP on June 11, 2026.IRS mandatory electronic filing for Forms 8955-SSA and 5500-EZOfficial IRS guidance on the 10-return mandatory e-filing threshold and aggregation rules. Official source reviewed for this MVP on June 11, 2026.DOL EFAST2 filer helpOfficial DOL guidance on electronic filing, IFILE, credentials, and approved software requirements. Official source reviewed for this MVP on June 11, 2026.IRS Form 5558 extensionOfficial extension form context for Form 5500-series returns. Official source reviewed for this MVP on June 11, 2026.IRS Form 14704 late-filer transmittalOfficial transmittal schedule for the Form 5500-EZ Delinquent Filer Penalty Relief Program. Official source reviewed for this MVP on June 11, 2026.IRS Revenue Procedure 2015-32Official revenue procedure establishing the Form 5500-EZ late-filer penalty relief fee framework. Official source reviewed for this MVP on June 11, 2026.

Last reviewed: June 10, 2026.