Form 5500-EZ for Solo 401(k): When and How to File

Quick Answer

Solo 401(k) plans must file Form 5500-EZ once total plan assets pass $250,000 at the close of the plan year. The deadline falls on the last day of the seventh month after your plan year ends — July 31st for calendar-year plans. A final filing is also required when you shut down the plan, regardless of the balance.

What Is Form 5500-EZ?

Form 5500-EZ is an annual information return used by one-participant retirement plans, including Solo 401(k)s. The form provides the IRS with information about the plan, its assets, and its status.

Unlike a tax return, Form 5500-EZ does not calculate taxes owed. Instead, it serves as a reporting and compliance document that helps the IRS monitor retirement plans and ensure they continue to meet applicable rules.

Many Solo 401(k) owners do not need to file the form when their plans are first established. However, once certain filing requirements are triggered, submitting Form 5500-EZ becomes an important part of maintaining compliance.

Who Must File Form 5500-EZ for a Solo 401(k)?

Here’s a closer look at who needs to file and the situations that trigger a filing requirement.

Understanding the One-Participant Plan Rule

Form 5500-EZ is generally used by one-participant retirement plans. These plans typically cover a business owner and, in some cases, the owner’s spouse.

If your retirement plan includes common-law employees, different reporting requirements may apply.

The $250,000 Asset Threshold Explained

The most common filing trigger is the plan asset threshold.

If the total value of all assets in your Solo 401(k) exceeds $250,000 at the end of the plan year, you are generally required to file Form 5500-EZ.

When determining whether you’ve crossed the threshold, you should consider the fair market value of all assets held within the plan, including investments, cash balances, and alternative assets.

When Multiple Solo 401(k) Plans Are Aggregated

Some business owners maintain more than one one-participant retirement plan.

In these situations, the IRS may require plan assets to be aggregated when determining whether the $250,000 filing threshold has been exceeded. Reviewing all retirement plans together is important to avoid accidentally missing a filing requirement.

Final-Year Filing Requirements

Even if your plan assets never exceed $250,000, a final Form 5500-EZ is generally required when a Solo 401(k) is terminated.

Many plan owners overlook this requirement because they assume the filing threshold still applies. However, the IRS typically expects a final filing when the plan is closed.

When Is Form 5500-EZ Due?

Once you know you need to file, the next step is understanding the deadline.

Standard Filing Deadline

Form 5500-EZ is generally due by July 31 of the year following the plan year. If your Solo 401(k) meets the filing requirements, it’s a good idea to start gathering account statements and plan information well before the deadline to avoid last-minute issues.

Calendar-Year vs. Fiscal-Year Plans

Most Solo 401(k) plans operate on a calendar year, which means the plan year ends on December 31. However, some plans may follow a fiscal year instead. If your plan uses a different year-end, your filing timeline may vary.

Before preparing your filing, confirm which type of plan year your Solo 401(k) follows.

Extension Rules and Available Filing Relief

If you need additional time to file, certain extensions may be available depending on your tax filing situation. However, it’s a good idea to gather your records early instead of waiting until the deadline approaches.

Important Dates Solo 401(k) Owners Should Know

A few simple reminders can help you stay organized throughout the year:

• End of the plan year: Determine your total plan assets.
• Early in the following year: Gather account statements and plan information.
• July 31: Standard Form 5500-EZ filing deadline.
• Final plan year: File Form 5500-EZ if you close the plan, regardless of the account balance.

How to File Form 5500-EZ Step by Step

Filing Form 5500-EZ is usually straightforward when your records are organized. Here’s how to do it:

1. Gather Your Solo 401(k) Information

Before starting the form, collect all relevant plan information, including:

• Plan name
• Employer Identification Number (EIN)
• Plan number
• Plan year information
• Participant information

Having these details available beforehand can make the filing process much smoother.

2. Determine Your Plan’s Fair Market Value

Next, calculate the fair market value of your Solo 401(k) as of the end of the plan year.

This includes all assets held within the plan, including alternative investments if your account contains them.

3. Complete Form 5500-EZ

Once you have the necessary information, complete each section of the form carefully. Double-check account balances, participant information, and identifying details before submitting it.

Simple data entry mistakes are one of the most common reasons filings need corrections.

4. File Electronically Through EFAST2

Many Solo 401(k) owners choose to file electronically through the EFAST2 system. Electronic filing can simplify the submission process and provide confirmation that the filing was received.

5. Paper Filing Options (When Applicable)

Depending on your circumstances, paper filing options may still be available. If filing by mail, make sure the form is completed accurately and submitted before the deadline.

6. Retaining Records for IRS Compliance

After filing, keep copies of Form 5500-EZ along with supporting documentation.

Maintaining organized records can be helpful if questions arise later or if the IRS requests additional information.

Common Form 5500-EZ Filing Mistakes

The IRS has identified several recurring issues that Solo 401(k) owners commonly encounter.

1. Miscalculating Total Plan Assets

One of the most common mistakes involves incorrectly calculating plan assets.

This often happens when alternative investments, private assets, or real estate holdings are not valued properly.

2. Forgetting to File After Crossing the $250,000 Threshold

Some plan owners assume they only need to file once their account reaches a much larger balance.

However, the filing requirement generally begins once total plan assets exceed $250,000 at year-end.

3. Missing a Final-Year Filing

Plan terminations frequently create compliance problems because owners assume no filing is required if the account balance falls below the threshold.

In many cases, a final Form 5500-EZ is still required.

4. Reporting Errors on Plan Information

Simple mistakes involving EINs, plan numbers, plan names, or participant information can delay processing and create unnecessary administrative issues.

5. Filing the Wrong Form

Some retirement plan owners accidentally file the wrong reporting form altogether.

Using the correct filing form is an important part of maintaining compliance and avoiding delays.

Penalties for Late or Missed Form 5500-EZ Filings

Failing to file Form 5500-EZ can become expensive very quickly. Here’s a closer look at the penalties:

IRS Penalties Explained

The IRS may assess a penalty of $250 per day for late Form 5500-EZ filings.

These penalties can accumulate rapidly, with a maximum penalty of $150,000 per return.

What Happens if You Miss the Deadline?

If a required filing is missed, penalties may continue to accrue until the issue is corrected.

In addition to financial consequences, unresolved filing issues can create administrative complications for your retirement plan.

How to Correct a Late Filing

If you discover that a filing was missed, it is generally best to address the issue as soon as possible rather than waiting for IRS correspondence.

Correcting the filing promptly may help reduce potential consequences.

Delinquent Filer Relief Programs

Fortunately, relief may be available through the IRS Late Filer Penalty Relief Program.

Under this program, eligible plan owners may be able to significantly reduce penalties. Rather than facing the standard daily penalty structure, filing fees may be capped at $500 per delinquent return, with a maximum cap of $1,500 per plan.

For plan owners who discover missed filings from prior years, this relief program can provide meaningful savings.

Frequently Asked Questions About Form 5500-EZ for Solo 401(k)