This checklist covers the recurring administrative obligations for Solo 401(k) plan owners. Use it each year to confirm your plan is current and compliant. Items are organized by timing. Not every item applies to every account, but review the full list annually.
Begin year-end asset valuation
Traded assets such as cryptocurrency or brokerage accounts should use the exchange value as of December 31. Assets with a more static value, such as real estate, can be valued within 60 days prio
r to year-end. For assets that require third-party valuation letters or appraisals, begin requesting them in November. Do not wait until year-end.
Make employee salary deferral contributions (corporate / W-2 wages)
In a corporate or W-2 environment, contributions must be made with the final payroll of the year. Do not miss this deadline.
Initiate RMDs if applicable
If you are subject to Required Minimum Distributions, calculate the amount due and initiate the distribution before December 31. Work with your CPA to confirm the correct amount. Failure to take a required distribution results in an IRS excise tax on the shortfall.
Review beneficiary designations
Confirm your beneficiary designations are current. Update them promptly if you have experienced a life change such as marriage, divorce, or the death of a named beneficiary. Keep a copy of your beneficiary designation form with your other estate planning documents.
Make employer profit sharing contributions
Employer profit sharing contributions may be made through the business tax filing deadline, including extensions. For corporate entities, this can be as late as September 15. For sole proprietors and pass-through entities, as late as October 15. Confirm the deadline for your business structure with your CPA.
Prepare the annual plan statement
Prepare a summary statement as of December 31 covering all participant accounts. The statement should document beginning and ending values for each asset, contributions, distributions, and any outstanding participant loan balances. This is an internal document but is required as part of your plan administration obligations.
Issue Form 1099-R for any distributions
If any participant took a distribution during the prior year, issue Form 1099-R. This form reports the distribution to the IRS and to the participant. It is also required for distributions that are rolled over to another plan. The deadline for furnishing Form 1099-R to recipients is January 31.
Issue 1099-NECs to vendors
If the plan paid any individual contractor, property manager, or service provider $600 or more during the prior calendar year, issue a Form 1099-NEC. Both the IRS copy and the vendor copy are due by January 31.
File Form 5500-EZ if required
If your plan assets exceeded $250,000 at any point during the calendar year, Form 5500-EZ is due by July 31.
Review business eligibility
Confirm your business continues to qualify as an owner-only enterprise. Monitor employee hours, review any new business interests you have acquired, and confirm your earned income remains active. If your eligibility status has changed, contact us before the next plan year ends.
Collect W-9s from new vendors
Before making any payment to a new vendor, collect a completed IRS Form W-9. File it with your plan records. This is required to issue a 1099-NEC at year-end and to document that the vendor is not a disqualified person.
Monitor participant loan repayments
If you have an outstanding participant loan, confirm repayments are being made on schedule and at least quarterly. A missed payment can trigger a deemed distribution, which is a taxable event. Track the outstanding balance and update it in your annual plan statement.
Retain all transaction records
Keep bank statements, purchase agreements, income receipts, expense receipts, and any contracts associated with plan investments. Do not allow gaps in your records.
File Form 990-T if required
If the plan received income qualifying as Unrelated Business Taxable Income (UBTI) or Unrelated Debt-Financed income (UDFI) exceeding $1,000 for the year, the plan must file Form 990-T. The Solo 401(k) is exempt from UDFI on leveraged real estate held directly, but other forms of debt like margin trading are not exempt. Work with your CPA to determine whether UBTI or UDFI applies and to meet the filing deadline, potentially including estimated tax payments.
Update contact information with all parties
If your address, phone number, or email address changes, update it with your plan document provider and all vendors, banks, and insurance carriers associated with the plan.
These situations require immediate attention:
Your business has hired or is planning to hire a qualifying employee. Solo 401(k) eligibility depends on owner-only status. Address this before it affects your plan.
A K-1 with a value in Box 20V. This indicates UBTI and may create a Form 990-T filing obligation. Share it with your CPA promptly.
A participant loan payment has been missed. A loan in default is treated as a taxable distribution. Cure the default as quickly as possible.
An investment opportunity that involves a transaction with yourself, a family member, or another disqualified person. Stop and consult a professional before proceeding. Prohibited transactions can disqualify the entire plan.
This information is provided for educational purposes only and should not be interpreted as tax, legal, or investment advice. Readers are encouraged to consult a qualified professional who can offer guidance based on their personal situation.