IRS Form 5310 Guide: Plan Termination Determination Rules

Introduction: What Is IRS Form 5310?

IRS Form 5310, titled Application for Determination for Terminating Plan, is an official federal tax application issued by the Internal Revenue Service (IRS). It is governed by the IRS Employee Plans division under Section 401(a) and Section 403(a) of the Internal Revenue Code (IRC) and the Employee Retirement Income Security Act (ERISA).

Employers and plan sponsors use Form 5310 when completely closing down an employer-sponsored retirement plan, such as a 401(k), profit-sharing, money purchase, or defined benefit pension plan. The form requests an official Determination Letter upon Termination from the IRS.

This determination letter confirms that closing the plan and distributing all accumulated assets will not adversely affect the plan’s tax-qualified status across its operational history.

Purpose of the Form

When an employer decides to terminate a retirement plan, all remaining plan assets must be liquidated and distributed to participants or rolled over into other qualified accounts. If the plan contained hidden document defects or operational errors, liquidating the plan could trigger retroactive disqualification.

Plan disqualification carries catastrophic tax consequences: participants lose the ability to roll over funds tax-free, distributed amounts become immediately taxable, and the employer may lose prior corporate tax deductions. Form 5310 provides a formal mechanism to have the IRS audit and approve the termination before or while final distributions occur.

Securing a favorable determination letter on Form 5310 acts as legal closure, providing written assurance to the employer, trustees, and participants that the termination complies fully with federal tax laws.

Who Needs to File / Use This Form

Form 5310 is filed by employers and plan administrators who are terminating a qualified defined contribution or defined benefit plan and want formal IRS approval. You should file Form 5310 if you are:

• Terminating a Defined Contribution Plan: Closing down a 401(k), profit-sharing, or stock bonus plan due to corporate restructuring, business closure, merger, or high administrative costs.
• Terminating a Defined Benefit Pension Plan: Liquidating a traditional pension or cash balance plan and distributing benefit liabilities through lump-sum payouts or insurance annuity purchases.
• Protecting Participant Rollovers: Sponsoring a plan with substantial account balances where participants require written assurance that their distributions remain eligible for tax-free IRA rollovers.

Who Is Exempt / Not Required to File

Filing Form 5310 is technically elective rather than legally mandatory, though strongly recommended as standard practice. Additionally, you do not use Form 5310 under the following circumstances:

• Ongoing Active Plans: Employers seeking determination letters for active, ongoing plans must file Form 5300 or Form 5307 instead.
• Partial Plan Terminations: If your company experiences a significant workforce reduction (typically 20% or more) resulting in a partial termination while the plan continues, use Form 5300.
• SEP and SIMPLE IRAs: Simplified Employee Pensions (SEPs) and SIMPLE IRA plans do not file Form 5310 to terminate; they are closed through internal employer resolutions and notifications to the financial custodian.
• Non-Qualified Plans: Executive deferred compensation plans under Section 409A cannot use Form 5310.

When to File

Form 5310 is an event-based filing tied to the formal termination of the retirement plan. Key timing milestones include:

• Plan Termination Resolution: The employer must first execute a formal corporate resolution establishing the plan’s effective termination date, halting all future benefit accruals or contributions, and fully vesting all participants.
• Application Window: Form 5310 is generally submitted either in advance of final asset liquidation or within a reasonable period around the effective termination date.
• Notice to Interested Parties: Employers must distribute a formal notice to all eligible employees, active participants, and beneficiaries between 10 and 24 days before submitting Form 5310 (or 7 to 21 days if the notice is posted electronically or in the workplace).

Where and How to File

The IRS requires all Form 5310 determination letter applications to be submitted electronically. Physical paper mail filings are no longer accepted.

• Pay.gov Electronic Submission: Plan sponsors or their designated ERISA attorneys and third-party administrators (TPAs) must complete Form 5310, compile all required plan documents and attachments, and upload the entire package as a single consolidated PDF via Pay.gov.
• IRS User Fee: The mandatory IRS Employee Plans user fee must be paid electronically through Pay.gov at the time of submission.

Always maintain a complete file copy of your submitted application package, Pay.gov payment receipts, and employee notification records in your permanent corporate benefits archives.

Step-by-Step Instructions to Fill Form 5310

Form 5310 is a comprehensive application covering employer details, plan characteristics, termination mechanics, and statutory compliance questions.

Section / Lines	Key Focus Areas	What to Enter / Select
Lines 1a – 2c	Plan Sponsor Information	Enter the legal employer name, physical address, Employer Identification Number (EIN), primary contact person, and telephone number.
Lines 3a – 3c	Authorized Representative	Provide contact details for your designated ERISA attorney, CPA, or enrolled actuary. Attach Form 2848 (Power of Attorney) if applicable.
Lines 4a – 5	Plan Identification	Enter the official plan name, 3-digit plan number (e.g., 001), date established, plan year-end date, and select the plan type (e.g., 401(k), profit-sharing, defined benefit).
Lines 6 – 9	Termination Specifics	State the effective termination date, the date the termination resolution was adopted, and the primary business reason for termination (e.g., corporate liquidation, business sale, cost).
Lines 10 – 13	Participants & Distributions	Report the total number of participants, total asset value at termination, confirm 100% immediate vesting for all affected workers, and describe the intended distribution methods (lump sums, direct rollovers, or annuity purchases).
Lines 14 – 20+	Statutory Compliance Checklist	Answer technical questions verifying coverage testing under Section 410(b), non-discrimination under Section 401(a)(4), top-heavy minimums, and defined benefit surplus asset reversion rules under Section 4980.

Mandatory 100% Vesting (Line 11)

Under federal tax law, all active participants must become 100% fully vested in their entire account balances or accrued benefits upon plan termination, regardless of the plan’s standard multi-year vesting schedule. Form 5310 requires you to certify that all non-vested forfeitures have been restored and fully vested.

Asset Reversions for Defined Benefit Plans

If you are terminating a defined benefit pension plan that holds excess assets after satisfying all participant liabilities, you must disclose whether any surplus will revert to the employer. Employer reversions are subject to strict excise taxes under IRC Section 4980.

Required Documents and Information Needed Before Filling

Before uploading your Form 5310 application to Pay.gov, assemble the following legal and financial records:

• Termination Resolution & Amendments: The formal corporate board resolution authorizing plan termination and all final interim amendments required to bring the plan into compliance with current tax law.
• Master Plan Document & Trust: A complete, signed copy of the current plan document, trust agreement, and all prior adoption agreements.
• Prior Determination Letters: Copies of the most recent IRS Determination Letter or Opinion Letter issued to the plan.
• Notice to Interested Parties: A copy of the formal notice delivered to employees, along with proof of delivery dates.
• Final Financial Statements: Balance sheets and asset statements showing total plan assets and liabilities as of the termination date.
• Form 2848: Power of Attorney and Declaration of Representative (if legal counsel is filing on your behalf).

Common Mistakes to Avoid

• Mailing Paper Forms: Attempting to submit physical paper copies to the IRS rather than uploading the consolidated PDF package through Pay.gov.
• Missing the Employee Notice Window: Submitting the application without providing the mandatory Notice to Interested Parties within the required 10-to-24-day advance window.
• Failing to Provide 100% Vesting: Forgetting to fully vest all participants upon termination, which is an immediate violation of IRC Section 411(d)(3).
• Distributing Assets Before Final Amendments: Liquidating assets before adopting all required interim tax law amendments (such as SECURE 2.0 statutory updates).
• Neglecting the Final Form 5500: Assuming Form 5310 replaces the annual Form 5500. A final Form 5500 (marked “Final Return”) must be filed after all assets are distributed to zero.

Penalties and Compliance Risks

While Form 5310 itself carries no late-filing fee because it is an optional application, improper plan termination creates severe liabilities:

• Plan Disqualification: If an unapproved terminating plan contains document or operational defects, the IRS can retroactively disqualify the plan. Employer deductions are disallowed, and trust earnings become fully taxable.
• Loss of Rollover Protection: Participants who rolled their balances into Traditional or Roth IRAs lose tax-deferred rollover treatment. The entire distribution becomes immediately taxable as ordinary income, plus potential early withdrawal penalties.
• Asset Reversion Excise Taxes: Sponsoring employers receiving surplus assets from a terminated defined benefit plan face a 20% to 50% excise tax under IRC Section 4980 on Form 5330.
• Form 5500 Penalties: Failing to file the final Form 5500 can trigger IRS fines of up to $250 per day and Department of Labor (DOL) penalties exceeding $2,500 per day.

Related Forms and Schedules

When closing a retirement plan, employers and administrators frequently work with these related IRS tax forms:

• Form 5500 / 5500-SF: Annual Return/Report of Employee Benefit Plan (must be filed as the “Final Return” once plan assets reach zero).
• Form 1099-R: Distributions From Pensions, Annuities, Retirement or Profit-Sharing Plans, IRAs, etc. (issued to all participants receiving final payouts).
• Form 5300: Application for Determination for Employee Benefit Plan (used for ongoing plans or partial terminations).
• Form 5310-A: Notice of Plan Merger or Consolidation, Spinoff, or Transfer of Plan Assets or Liabilities.
• Form 5330: Return of Excise Taxes Related to Employee Benefit Plans (used to pay excise taxes on defined benefit asset reversions).
• Form 2848: Power of Attorney and Declaration of Representative.

Frequently Asked Questions (FAQs)

1. Is filing Form 5310 legally mandatory when closing a retirement plan?

No. Applying for an IRS Determination Letter on termination is voluntary. However, it is the only way to obtain official IRS written confirmation that your plan termination satisfies all tax-qualification rules, protecting employer tax deductions and participant rollovers.

2. What does 100% vesting upon termination mean?

Under IRC Section 411(d)(3), every participant who is active on the termination date must become 100% fully vested in all employer contributions, regardless of how many years of service they have completed.

3. Can we distribute plan assets before receiving the IRS Determination Letter?

Yes. Employers can distribute assets before the letter arrives, but many plan sponsors choose to hold back final distributions until the favorable IRS letter is issued to avoid the risk of distributing from a disqualified plan.

4. What is the difference between Form 5310 and Form 5300?

Form 5300 is used for ongoing, active retirement plans seeking determination letters for initial adoption, major amendments, or partial terminations. Form 5310 is used exclusively when a plan is undergoing complete, final termination.

5. Do I still need to file Form 5500 if I submit Form 5310?

Yes. You must continue filing annual Form 5500 reports every year until all plan assets have been distributed to zero, at which point you file a final Form 5500 marked “Final Return.”

6. How long does the IRS take to issue a Determination Letter on Form 5310?

IRS processing times vary based on agent workload and the complexity of the plan, but most Form 5310 determination letters are issued within 6 to 12 months from the date of electronic submission.

Conclusion

IRS Form 5310 is the gold standard for employers seeking to terminate an employee retirement plan cleanly and safely. By obtaining a favorable IRS Determination Letter upon termination, business owners and plan fiduciaries eliminate the threat of retroactive plan disqualification, protect corporate tax deductions, and safeguard their workers’ retirement savings.

To ensure a smooth termination process, adopt all required final amendments, provide mandatory 100% vesting to all participants, deliver timely notices to interested parties, upload your complete consolidated application to Pay.gov, and file your final Form 5500 once all account balances are distributed.