Does Your Spouse Have to Be Your 401(k) Beneficiary?

Under federal law, your spouse is automatically the beneficiary of your 401(k), and you cannot name anyone else unless your spouse signs a specific written waiver. This rule comes from the Employee Retirement Income Security Act and applies no matter what state you live in, what your will says, or what you and your spouse have agreed to verbally.

Why Your Spouse Is the Default Beneficiary

ERISA governs employer-sponsored retirement plans, including 401(k)s. Under 29 U.S.C. § 1055, when a married participant dies before retirement, the surviving spouse receives the account balance.¹ Most 401(k) plans are structured as profit-sharing plans and are technically exempt from the more complex annuity rules, but that exemption exists only because these plans already require the full balance to go to the surviving spouse.²

Because 401(k)s fall under federal jurisdiction, these rules override state marital property and community property laws. A will, a trust document, or a handwritten note has no effect on a 401(k) beneficiary designation. The plan administrator pays whoever appears on the plan’s official beneficiary records, and for a married participant, that person is the spouse by default.¹

How to Name Someone Other Than Your Spouse

If you want anyone else to inherit your 401(k), your spouse has to sign a written waiver. A verbal agreement or an email will not do it, and neither will a beneficiary form you fill out alone. The Internal Revenue Code lays out specific requirements, and missing any one of them invalidates the waiver.

The waiver must either name the specific non-spouse beneficiary who will receive the funds, or expressly allow you to change beneficiaries in the future without asking again. Vague language about giving up “all rights” may not hold up.³
Your spouse’s consent must acknowledge the effect of waiving the right to the account balance.
Your spouse’s signature must be witnessed by a plan representative or a notary public. A signature witnessed by you, a family member, or a friend does not count.³

After your spouse signs, you submit the paperwork to your plan administrator. The change is effective only once the administrator accepts it. If any piece is missing, the original spousal designation stays in place no matter what you intended.

Remote Notarization

Traditionally the spouse had to appear physically before a notary or plan representative. The IRS has proposed rules that would permanently allow remote witnessing over live audio-video, as long as the session complies with the notary’s state law requirements.⁴ Those rules are not yet final, but the IRS has said plans can rely on them in the meantime. Ask your plan administrator whether they accept remote notarization.

Prenuptial Agreements Do Not Work

This one surprises people. A prenuptial agreement cannot serve as a valid spousal waiver, no matter how clearly it addresses retirement assets. The Internal Revenue Code requires consent from a “spouse,” and a fiancée is not a spouse. Courts have consistently held that pre-marriage waivers fail this requirement.³

Postnuptial agreements have a related problem. Courts have rejected postnups that merely contemplate a future waiver or include general language about retirement benefits. The waiver has to be a standalone document that meets every ERISA requirement on its own. If your prenup or postnup discusses your 401(k), you still need a separate spousal waiver signed after the wedding, properly witnessed, that meets each of the requirements above.

Marriage Cancels Your Old Beneficiary Designation

If you named a beneficiary while you were single and later married, federal law automatically gives your new spouse the right to your 401(k) balance. Your earlier designation, whether it named a parent, a sibling, a child, or anyone else, is effectively overridden. The plan must pay the surviving spouse unless a new, properly executed waiver is signed after the wedding.

This happens by operation of law, not because anyone at your company updated your paperwork. Many participants never learn that their pre-marriage designations no longer control. If you marry and still want a non-spouse beneficiary, you have to go through the full waiver process with your new spouse.

Divorce Does Not Remove Your Ex

A divorce decree does not automatically remove your ex-spouse from your 401(k) beneficiary designation. In Egelhoff v. Egelhoff, the Supreme Court held that ERISA preempts state laws that would automatically revoke a former spouse’s beneficiary status upon divorce.⁵ The plan administrator is bound to follow the plan documents, and if the plan documents still name the ex-spouse, that is who gets paid.

The practical takeaway is blunt. If you divorce and don’t update your beneficiary form, your ex-spouse may inherit your entire 401(k), regardless of what your divorce decree says about retirement assets. Retirement assets are often divided at divorce through a Qualified Domestic Relations Order,⁶ but even after a QDRO transfers a portion of your account to your ex, the remaining balance still follows whatever beneficiary designation is on file. If you remarry, your new spouse becomes the default beneficiary of that remaining balance.

If You Are Not Married

None of the spousal consent rules apply if you are not legally married. You can name any person, trust, charity, or other legal entity as your beneficiary without anyone else’s permission.⁷ You can split the account among multiple beneficiaries in any percentages, and you can change your designation any time by filing updated paperwork with your plan administrator.

If you name no one, the plan document controls. Most plans direct the funds to the participant’s estate, which sends the money through probate. That process is slower, more expensive, and eliminates some of the tax-deferral options that a named beneficiary would have.

IRAs Follow Different Rules

Individual Retirement Accounts are not covered by ERISA’s spousal consent requirements. With a traditional IRA or Roth IRA, no federal law requires your spouse to be the beneficiary, and you can name whoever you want without a waiver.

The exception involves community property states. There, your spouse may have a community property interest in IRA contributions made during the marriage, and naming someone else as beneficiary for more than 50% of such an IRA could be challenged by the surviving spouse in court. Couples in those states sometimes use marital property agreements to designate each spouse’s IRA as separate property. The broader point is that a 401(k) requires spousal consent to name a non-spouse beneficiary; an IRA generally does not, unless state community property law says otherwise.

Why the Default Rule Favors Spouses

The tax code gives a surviving spouse options no other beneficiary has, which is part of why the default rule exists.

A surviving spouse can roll the inherited 401(k) into their own IRA. Doing so resets the required minimum distribution clock: the spouse does not have to start taking withdrawals until reaching their own RMD age, currently 73. They can also name new beneficiaries on the rolled-over account.⁷
Instead of rolling over, a surviving spouse can keep the account as an inherited 401(k) and stretch distributions over their own life expectancy.
If the account holder died before their required beginning date, the surviving spouse can delay distributions until the year the deceased would have turned 73.⁷

Non-spouse beneficiaries have fewer options. Most must empty the entire inherited account within 10 years of the account holder’s death.⁷ That compressed timeline can push large amounts into the beneficiary’s taxable income over a short period and bump them into higher tax brackets. A limited group of “eligible designated beneficiaries,” including minor children, disabled individuals, and people not more than 10 years younger than the deceased, can still use life-expectancy distributions. Most adult children and other common beneficiaries are stuck with the 10-year rule.

These tax differences are worth factoring into any decision to name someone other than your spouse. If a spousal waiver still makes sense for estate planning reasons, understanding the tax cost to the alternate beneficiary helps everyone involved make an informed choice.

1
Office of the Law Revision Counsel. 29 U.S. Code 1055 – Requirement of Joint and Survivor Annuity and Preretirement Survivor Annuity
2
Internal Revenue Service. Retirement Topics – Qualified Joint and Survivor Annuity
3
Office of the Law Revision Counsel. 26 U.S.C. 417 – Definitions and Special Rules for Purposes of Minimum Survivor Annuity Requirements
4
Internal Revenue Service. Notice of Proposed Rulemaking – Use of an Electronic Medium to Make Participant Elections and Spousal Consents
5
Justia Law. Egelhoff v. Egelhoff, 532 U.S. 141 (2001)
6
U.S. Department of Labor. QDROs Chapter 1 – Qualified Domestic Relations Orders: An Overview
7
Internal Revenue Service. Retirement Topics – Beneficiary