Yes, a trust can be named as the beneficiary of a 401(k), but the IRS will only respect it for distribution purposes if the trust meets four requirements under Treasury Regulation § 1.401(a)(9)-4. Get that right and the human beneficiaries inside the trust drive the payout schedule. Get it wrong and the account may have to be emptied in five years, with a compressed tax bill to match. Married account owners have an extra step: federal law requires written spousal consent before anyone other than the spouse can be the primary beneficiary.
The Four IRS Requirements for a See-Through Trust
The IRS does not treat a trust as a person. It will, however, “see through” a qualifying trust to the individuals named inside it, and those individuals’ ages and status then set the distribution timeline. Treasury Regulation § 1.401(a)(9)-4 requires all four of the following:
- The trust must be valid under the law of the state where it was created.
- The trust must be irrevocable, or must become irrevocable at the account owner’s death. A revocable living trust satisfies this automatically because it converts on death.
- The beneficiaries must be identifiable from the trust document. Vague language, or naming non-human beneficiaries like charities or corporations, can disqualify the trust.
- The trustee must deliver a copy of the trust document to the 401(k) plan administrator no later than October 31 of the year after the account owner’s death.
Miss any one of these and the plan treats the account as though there is no designated individual beneficiary, which pushes the payout into much faster and less flexible timelines.1eCFR. 26 CFR 1.401(a)(9)-4 – Determination of the Designated Beneficiary
Spousal Consent If You Are Married
Under the Employee Retirement Income Security Act, a married participant’s spouse has a legal right to at least 50% of the account’s death benefit. Naming a trust as primary beneficiary overrides that right, so the spouse must waive it in writing.2Office of the Law Revision Counsel. 29 U.S. Code 1055 – Requirement of Joint and Survivor Annuity and Preretirement Survivor Annuity
The waiver has to acknowledge the effect of giving up the survivor benefit, identify the trust (or other beneficiary) taking the funds instead, and be witnessed by either a plan representative or a notary public. A signature on the beneficiary form by itself is not enough. The waiver also generally has to be tied to the specific beneficiary being named; a blanket consent to future designations typically requires express language.
A designation made without valid spousal consent can be challenged after your death and potentially voided, leaving the plan administrator to distribute assets under its default rules rather than to your intended trust.3Internal Revenue Service. Retirement Topics – Qualified Pre-Retirement Survivor Annuity (QPSA)
Filling Out the Beneficiary Designation Form
The beneficiary form on file with the plan is what actually controls where your 401(k) goes. It overrides your will and your trust document, and plan administrators pay it strictly.4U.S. Department of Labor. Current Challenges and Best Practices Concerning Beneficiary Designations in Retirement and Life Insurance Plans
To name the trust correctly, you’ll need three things from the trust agreement: the trust’s full legal name as it appears in the document, the date the trust was executed, and the trust’s Taxpayer Identification Number. Some revocable trusts use the grantor’s Social Security number during the grantor’s lifetime, but you should obtain a separate EIN from the IRS if the trust will receive retirement plan assets after your death. The form also asks for the current trustees, since those are the people the plan will deal with when it’s time to transfer the account.
You can typically get the form from your employer’s HR department or the plan provider’s website. If the trust contains sub-trusts (separate shares for each child, for example, or a special needs share for one beneficiary), use precise language identifying which portion of the trust receives the 401(k) funds. After submitting the form, wait for written confirmation from the plan administrator and keep a copy with your estate planning documents. If the trust name changes or you replace a trustee, update the form promptly; a mismatch between the form and the current trust makes life harder for your successor trustee.
Conduit Trust or Accumulation Trust
See-through trusts come in two flavors, and the choice shapes both control and taxes.
Conduit Trust
A conduit trust requires the trustee to pass every dollar received from the 401(k) straight through to the named beneficiary. Nothing stays in the trust. Because the money flows through, only the primary beneficiary’s age and status matter for the distribution schedule; the IRS ignores remainder beneficiaries entirely. Distributions land on the beneficiary’s personal return and are taxed at that person’s individual rate, which is almost always lower than trust rates.
The tradeoff is control. If the reason you wanted a trust was to keep a beneficiary from spending the money too quickly, a conduit trust undercuts that purpose because every distribution must be handed over as it comes in.
Accumulation Trust
An accumulation trust lets the trustee hold distributions inside the trust instead of passing them through, preserving discretion over when and how the beneficiary receives funds. That is the main reason people use trusts for retirement assets in the first place.
The cost is tax treatment on two fronts. First, the IRS counts both primary and remainder beneficiaries when determining the distribution schedule, so the oldest possible recipient sets the pace. Second, income retained inside the trust is taxed at trust rates, which hit the top 37% federal bracket at just $16,000 of taxable income in 2026. For comparison, an individual filer doesn’t hit that same bracket until well over $600,000. A $100,000 distribution retained inside an accumulation trust faces roughly $32,000 in federal income tax; the same money taxed on a beneficiary’s return at 22% or 24% costs substantially less.5IRS. 2026 Estimated Income Tax for Estates and Trusts
How Long the Trust Has to Take the Money Out
The SECURE Act of 2019 eliminated the old lifetime “stretch” for most non-spouse beneficiaries. For most trust beneficiaries, the entire 401(k) must be withdrawn by the end of the tenth calendar year after the account owner’s death.6IRS. Retirement Plan Distributions After SECURE 1.0 and SECURE 2.0
Whether annual withdrawals are required during that 10-year window depends on when the account owner died relative to their required beginning date (RBD). The RBD is the deadline for starting required minimum distributions. Under SECURE 2.0, that date is April 1 of the year after turning 73 for people born between 1951 and 1959, and April 1 of the year after turning 75 for people born in 1960 or later.7Congressional Research Service. Required Minimum Distribution (RMD) Rules for Original Owners of Retirement Accounts
If the account owner died before the RBD, the trust beneficiary only has to empty the account by the end of year 10. There is no set schedule along the way. If the owner died on or after the RBD, the IRS’s finalized regulations require annual minimum distributions in each of the 10 years, calculated using the beneficiary’s life expectancy, with whatever remains due by the end of year 10. The IRS expects full compliance with those annual amounts starting in 2025.
Eligible Designated Beneficiaries Still Get a Stretch
A narrow group of trust beneficiaries can still take distributions over their own life expectancy: the account owner’s surviving spouse, a beneficiary who is disabled or chronically ill, a beneficiary not more than 10 years younger than the account owner, and the account owner’s minor child (whose stretch converts to the 10-year clock at the age of majority). To use the life-expectancy stretch for a disabled or chronically ill beneficiary, the trust generally must be structured for that individual’s sole benefit.
What Happens If the Trust Fails See-Through Status
If the trust does not qualify as a see-through trust, the IRS treats the account as having no designated individual beneficiary. When the account owner died before the RBD, the entire account has to be emptied within five years. When the owner died after the RBD, distributions are based on the owner’s remaining life expectancy, which is typically a shorter window than the 10-year rule would give.8Internal Revenue Service. Publication 590-B (2025) – Distributions from Individual Retirement Arrangements (IRAs)
Penalty for a Missed Distribution
Missing a required distribution triggers a 25% excise tax on the amount that should have come out. Correct the shortfall within two years and the penalty drops to 10%. Either version gets reported on IRS Form 5329.9Internal Revenue Service. Retirement Plan and IRA Required Minimum Distributions FAQs
Roth 401(k) Named to a Trust
A trust can also be named as the beneficiary of a Roth 401(k). The 10-year rule and the eligible designated beneficiary categories work the same way; what changes is the tax picture. Qualified distributions from a Roth designated account are not included in gross income, provided the account has been open at least five tax years before the distribution.10Office of the Law Revision Counsel. 26 U.S. Code 402A – Optional Treatment of Elective Deferrals as Roth Contributions
Because there is nothing to tax on the way out, the compressed trust brackets stop mattering. An accumulation trust funded with Roth 401(k) money can retain distributions without triggering the punishing rates that hit accumulation trusts holding traditional 401(k) assets. One caveat: if the trust does not qualify as see-through, the pre-SECURE rules for non-individual beneficiaries apply, which can force the five-year rule even though the money remains tax-free.11Internal Revenue Service. Retirement Topics – Beneficiary
Special Needs Trusts
One of the strongest reasons to name a trust as a 401(k) beneficiary is to protect a disabled or chronically ill family member. A properly structured special needs trust can qualify the beneficiary as an eligible designated beneficiary, preserving life-expectancy distributions rather than the 10-year rule. This is one of the few remaining ways to stretch inherited 401(k) distributions after the SECURE Act.
To qualify, the trust must be for the sole benefit of a person who is disabled (unable to engage in substantial gainful activity for at least 12 months) or chronically ill (unable to perform at least two activities of daily living without assistance for an indefinite period). The trust must meet all the standard see-through requirements, must be irrevocable at the account owner’s death, and cannot allow the trustee to distribute trust assets during the beneficiary’s lifetime to anyone who is not disabled or chronically ill.
SECURE 2.0 added helpful flexibility: naming a charity as the remainder beneficiary of a special needs trust no longer disqualifies the trust from see-through treatment. Before that fix, a charitable remainder was a common drafting trap because a charity is not an individual, and its presence blocked look-through status for the trust as a whole.1eCFR. 26 CFR 1.401(a)(9)-4 – Determination of the Designated Beneficiary