HR Glossary | 4 minute read

Supplemental Executive Retirement Plan (SERP)

A supplemental executive retirement plan, or SERP, is a nonqualified retirement arrangement that an employer offers to a select group of executives. It pays benefits on top of what qualified plans such as a 401(k) or pension allow, usually to replace income that tax limits would otherwise cut off.

Because a SERP is not a qualified plan, it can be tailored to the individual. That flexibility is the main reason employers use it to attract and retain senior leaders.

How Does a SERP Work?

The employer promises a future benefit, such as a percentage of final pay or a set account balance, payable after retirement or another event. The promise is documented in a plan agreement that sets vesting, the payment schedule and what happens if the executive leaves.

SERPs come in two broad forms. A defined benefit SERP promises a formula-based amount, while a defined contribution SERP credits an account with employer contributions and earnings.

Most SERPs are unfunded, meaning the employer pays from general assets when benefits come due. Some employers set aside assets informally through a trust or insurance policies to prepare, but those assets generally stay available to the employer's creditors.

Who Can Participate in a SERP?

The Department of Labor describes top hat plans as unfunded or insured pension plans for a select group of management or highly compensated employees. A SERP usually fits that description, which is what lets it avoid many ERISA rules.

Employers must still handle filing. The Department of Labor requires plan administrators to file a top hat statement electronically, and a separate filing is needed for a new top hat plan.

Eligibility is a design decision, so employers should keep the group narrow and tied to objective criteria. Covering a broad group can threaten the plan's top hat status.

How Are SERP Benefits Taxed?

In general, the executive is taxed when benefits are paid, and the employer takes a deduction at that time. Social Security and Medicare taxes may apply earlier, when benefits vest, under special timing rules.

Section 409A of the Internal Revenue Code governs when deferrals are elected and when payments can be made. A plan that fails those rules can trigger additional tax and penalties for the executive, so plan design and administration need careful attention.

Because the rules are technical, employers should have counsel and a tax adviser review the agreement before it is signed.

How Is a SERP Different From a Qualified Plan?

Feature	SERP	Qualified plan such as a 401(k)
Contribution limits	None set by tax law	Annual limits apply
Who can participate	Select executives	Broad employee group, with nondiscrimination rules
Asset protection	Employer's general creditors can reach assets	Held in trust for participants
Employer deduction	When benefits are paid	When contributions are made

The qualified versus nonqualified retirement plans comparison covers the wider set of differences, and the deferred compensation page explains the concept behind these arrangements.

What Should Employers Consider Before Adopting a SERP?

A SERP is a long-term commitment, so employers should weigh cost and risk before offering one. The promised benefit becomes a liability on the books, and informal funding through insurance or a trust adds its own administration.

Design choices shape the retention value. Longer vesting schedules, forfeiture on early departure and clear change-of-control terms all affect whether the plan keeps leaders in place.

Governance matters too. Boards and compensation committees usually approve a SERP, and they should receive projections of cost under different retirement ages and performance scenarios.

How Can HR Cloud Help With SERP Records?

Nothing on HR Cloud's published pages describes nonqualified plan administration. People HRIS can keep the employee record and agreements organized through secure document storage with version tracking and e-forms and e-signatures.

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Frequently Asked Questions

Q: Is a SERP the same as a 401(k)?

A: No. A 401(k) is a qualified plan open to a broad group with contribution limits. A SERP is a nonqualified arrangement for select executives with no such limits.

Q: Who pays for a SERP?

A: The employer, usually from general assets when benefits become payable. Executives generally do not contribute, though some SERPs allow deferrals.

Q: Is a SERP benefit guaranteed?

A: It is a promise from the employer, so it depends on the employer's ability to pay. Participants are generally unsecured creditors if the company fails.

Q: What does vesting mean in a SERP?

A: Vesting sets when the executive earns the right to the benefit, often after a number of years of service or at a specified age.

Q: Can a SERP be changed after it is signed?

A: Only under the plan's terms and within tax rules. Changes to payment timing can trigger Section 409A concerns, so counsel should review any amendment.

Q: Do SERPs need to be filed with the government?

A: Top hat plans must file a statement with the Department of Labor to qualify for the reduced reporting treatment, and the filing is made electronically.