Does Your Spouse Automatically Get Your 401(k)? ERISA vs. IRA Rules

Short answer: For a 401(k), yes — federal law makes your spouse the automatic 100% death beneficiary the day you marry, no matter what your beneficiary form says, unless your spouse signs a written waiver witnessed by a notary or plan representative (IRC §401(a)(11)(B)(iii), §417(a)(2)). For an IRA, no — there is no federal consent requirement, and the beneficiary form alone controls. People constantly conflate the two, and the difference decides real money in second marriages and after divorces. California’s community-property rules add a separate state-law layer for IRAs, but they don’t change the federal 401(k) rule.

Figures verified against IRC §§401(a)(11), 417, 29 U.S.C. §1055, Egelhoff v. Egelhoff, 532 U.S. 141 (2001), and Prob. Code §5040, 2026. This is general information, not legal advice for your situation.

The 401(k) rule: your spouse owns the death benefit on the wedding day

ERISA-covered retirement plans — the standard workplace 401(k) — carry a federal spousal guarantee. A typical 401(k) or profit-sharing plan stays out of ERISA’s annuity requirements only if the participant’s account is payable in full to the surviving spouse at death (IRC §401(a)(11)(B)(iii); the ERISA parallel is 29 U.S.C. §1055). The only way around it is spousal consent under §417(a)(2): a written waiver, signed by the spouse, acknowledging its effect, witnessed by a notary or a plan representative.

Read that back slowly: your spouse’s right doesn’t come from being named — it comes from being your spouse. A form naming your kids, your trust, your sibling — none of it beats an un-waived spouse.

One wrinkle: §417(d) lets a plan require one year of marriage before the spousal right attaches. That’s plan-optional — some plans adopt it, many don’t — so never assume a one-year grace period exists. The plan document answers it; the plan administrator can tell you in one phone call.

IRAs run on completely different rules

None of the above applies to an IRA. IRC §408 has no analog to §417 — no automatic spousal death benefit, no federal consent requirement. Whoever is named on the IRA custodian’s beneficiary form gets the account. Full stop. That’s why beneficiary designations beat wills so reliably, for better and worse.

California adds a state-law layer: an IRA funded with earnings during marriage is community property (Fam. Code §760), so a spouse may have a community-property claim to their half regardless of the form. But that’s a state-law property claim to be asserted, not an ERISA right the custodian enforces automatically. If a community-property dispute over an account turns into a fight, that’s litigation — not what Eric does — and he’ll point you to the right litigator for free. The planning move is simpler: make the form and the property agreement match your actual intent so nobody has to fight.

The divorce trap: Egelhoff and the ex-spouse who still collects

California tried to solve the forgotten-ex-spouse problem by statute. Probate Code §5040 treats a former spouse as having predeceased you for most nonprobate transfers — a divorce automatically knocks the ex off the payout, unless an exception applies (an irrevocable designation, clear evidence you meant to keep the ex, or a court order).

But §5040 cannot reach a 401(k). In Egelhoff v. Egelhoff, 532 U.S. 141 (2001), the U.S. Supreme Court held that ERISA preempts state revocation-on-divorce statutes: the plan pays the named beneficiary, even a long-divorced ex-spouse. The preemption is federal — no California statute can write around it. (The Court reached the same result for federal employee life insurance in Hillman v. Maretta, 569 U.S. 483 (2013).) So the split rule after a California divorce is stark:

• 401(k) with the ex still named: the ex collects. Your will, your trust, and §5040 are all beside the point.
• IRA with the ex still named: §5040 cuts the ex off (absent an exception), because no federal statute stands in the way.

The fix costs nothing: after any divorce, update every beneficiary form directly with the plan and the custodian, and get written confirmation.

The blended-family scenario nobody prices in

Here’s where the 401(k) rule bites hardest. Say a Thousand Oaks widower has a $900,000 401(k) and two adult kids from his first marriage, named as his beneficiaries for years. He remarries. On the wedding day, his new spouse becomes the automatic 100% death beneficiary of that 401(k) — the form naming his kids is now legally inert unless the new spouse signs a §417 notarized waiver. If he dies without that waiver, the kids get nothing from the account, whatever his will, his trust, or his prenup’s general language says.

This isn’t an argument against remarriage; it’s an argument for sequencing. In a blended-family estate plan, the 401(k) waiver conversation happens deliberately, soon after the wedding — alongside the trust, the IRA forms, and the house title. The waiver is the new spouse’s voluntary, informed choice. Some couples sign one; many decide the survivor should keep the account. Either answer works when it’s chosen instead of stumbled into. And the income-tax mechanics for whoever ultimately inherits — spouse rollover versus the 10-year payout rules — are a job to walk through with the plan administrator and your CPA, whose lanes those are.

Does my spouse automatically inherit my 401(k)?

Yes, if it’s an ERISA plan like a standard workplace 401(k). Federal law makes your surviving spouse the beneficiary of 100% of the account (IRC §401(a)(11)(B)(iii)) unless they’ve signed a §417(a)(2) waiver — written, acknowledging its effect, witnessed by a notary or plan representative. A beneficiary form naming someone else doesn’t override an un-waived spouse.

Can I name my children as 401(k) beneficiaries instead of my spouse?

Only with your spouse’s notarized (or plan-representative-witnessed) consent on the plan’s waiver form. Without it, the designation naming your kids is ineffective as against your spouse’s federal right. This is the single most common surprise in second marriages — the form looks valid, and it isn’t.

Does the same spousal rule apply to my IRA?

No. IRAs have no federal spousal-consent requirement — the custodian pays whoever the beneficiary form names. In California, a spouse may separately have a community-property claim to their half of an IRA funded during the marriage (Fam. Code §760), but that’s a state-law claim, not an automatic right the custodian enforces.

Will my ex-spouse get my 401(k) if I forgot to change the beneficiary?

Very likely yes. Under Egelhoff v. Egelhoff (2001), ERISA preempts California’s revocation-on-divorce statute, so the plan pays the named beneficiary even after the divorce. Probate Code §5040 does protect you on an IRA — the ex is treated as predeceased there, absent an exception — but it cannot save a 401(k). Update the form directly with the plan.

Is there a one-year marriage requirement before my spouse gets 401(k) rights?

Only if your specific plan adopted one. IRC §417(d) permits — but does not require — a plan to condition the spousal benefit on one year of marriage. Many plans skip it, which means the right attaches on the wedding day. Ask the plan administrator what your plan document says.

Can a prenup waive my spouse’s 401(k) rights?

Generally no, not by itself. The §417(a)(2) consent must be signed by a spouse, on the plan’s terms, with the required witnessing — and a fiancé isn’t a spouse yet. The reliable sequence is: marry, then have the new spouse sign the plan’s waiver form. A prenup can record the couple’s agreement, but the plan waiver is the document that actually moves the money.

The bottom line

One sentence sorts almost every case: 401(k)s follow federal spousal rights; IRAs follow the form. If you’re married, your 401(k) already belongs to your spouse at death unless they’ve formally waived it — so blended families need the waiver conversation, on purpose, after the wedding. If you’re divorced, assume nothing: the ex on a 401(k) form still collects, while §5040 quietly fixes the IRA. Pull your beneficiary confirmations this month and read the names. If what you find doesn’t match what you intend — or you’re remarrying with kids from a first marriage and want the accounts, trust, and forms pulling in the same direction — Talk to Eric.

Sources: IRC §401(a)(11)(B)(iii); IRC §417(a)(2), (d); 29 U.S.C. §1055; Egelhoff v. Egelhoff, 532 U.S. 141 (2001); Hillman v. Maretta, 569 U.S. 483 (2013); Cal. Prob. Code §5040; Cal. Fam. Code §760.