The 120-hour rule is a default survivorship period: to inherit from someone, a beneficiary generally has to outlive that person by at least five full days. If they don’t, the law treats them as having died first, and the property passes to whoever would have taken it if the beneficiary had never been in line. The rule comes from the Uniform Probate Code and the revised Uniform Simultaneous Death Act, and a majority of states have adopted some version of it.
The point is practical. When two people die close together in time, the rule stops the same property from running through two probate estates back to back, which would double the court costs and could hand assets to heirs the original owner never meant to benefit.
How the Five-Day Clock Works
The clock starts at the decedent’s moment of death and runs continuously for 120 hours. Missing it by minutes is enough to disqualify the beneficiary from inheriting that asset.
The evidence standard is deliberately strict. Survival for the full period has to be shown by clear and convincing evidence, not just a probability. If the exact time of either death can’t be pinned down, the default assumption is that the beneficiary did not survive long enough. That presumption keeps families out of drawn-out litigation when accidents, disasters, or shared medical emergencies make a precise timeline impossible.
Two sections of the Uniform Probate Code carry the rule. Section 2-104 covers intestate succession, which is what happens when someone dies without a will. Section 2-702 applies the same 120-hour requirement to wills, trusts, and other written instruments that direct how property passes at death. States vary: some still use the older Uniform Simultaneous Death Act, which only addressed truly simultaneous deaths, while others have adopted the revised version with the five-day window.
Which Assets the Rule Reaches
The rule applies more broadly than many people expect. It governs intestate succession, property passing under a will or trust, and some non-probate transfers.
Joint tenancy is where it bites hardest. If two joint tenants die within 120 hours of each other and there’s no clear evidence of who went first, the property doesn’t flow to one survivor’s estate as a whole. It splits in half: one portion is distributed as if one owner survived, the other as if the second did. Instead of the property staying together with a surviving owner, it ends up divided between two separate estates.
Life insurance and retirement accounts with named beneficiaries are also within reach. If the named beneficiary doesn’t clear the 120-hour threshold, the proceeds pass to a contingent beneficiary or revert to the estate. An outdated beneficiary form with no backup can send life insurance straight into probate for that reason alone.
A Note on 401(k)s and Pensions
Employer-sponsored retirement plans are different. These plans are governed by the federal Employee Retirement Income Security Act, and ERISA often preempts state law. In Egelhoff v. Egelhoff, the Supreme Court held that ERISA preempts state laws binding plan administrators to particular rules for determining who receives benefits.1U.S. Department of Labor. Current Challenges and Best Practices Concerning Beneficiary Designations in Retirement and Life Insurance Plans
Whether a state’s 120-hour rule reaches an ERISA plan is genuinely unsettled. The Department of Labor has said the effect of state survivorship laws on ERISA plans is unclear, and recommends that plans write their own survivorship and simultaneous-death provisions into the plan documents.1U.S. Department of Labor. Current Challenges and Best Practices Concerning Beneficiary Designations in Retirement and Life Insurance Plans If you have a sizable 401(k) or pension, check whether the plan document addresses simultaneous death. If it doesn’t, your family could face a dispute over whether state or federal rules control.
Exceptions That Override the Default
Three main exceptions pull a situation out from under the 120-hour default.
Escheat prevention. The rule does not apply if enforcing it would push the entire estate to the state because no qualifying heir survives long enough. The exception keeps the survival requirement from accidentally disinheriting everyone and handing the estate to the government.
The governing instrument. A will, trust, deed, or insurance contract that contains its own survivorship clause controls over the statutory default. A trust requiring a beneficiary to survive by 30 days replaces the 120-hour period with 30 days. A will saying “whether or not my spouse survives me” removes the survival requirement entirely. This is the exception that matters most in day-to-day estate planning, and custom survivorship clauses typically run from five to sixty days.
Children in gestation. A child conceived before the decedent’s death but born afterward is treated as having been alive at the time of death, as long as the child then lives at least 120 hours after birth. The exception protects inheritance rights for children born shortly after a parent dies.
Where the Property Goes Instead
When a beneficiary fails to clear 120 hours, the law treats them as having died first, and the property moves to the next person in line. Where that is depends on the document and what backups it contains.
If the will names a contingent beneficiary, that person takes. If no backup is named, the gift falls into the residuary estate, which is the catch-all portion that absorbs anything not specifically given to someone. If there’s no residuary clause either, the property passes under state intestacy law as if the decedent had no will for that asset.
Anti-Lapse Statutes
Most states have anti-lapse statutes that redirect the gift to the failed beneficiary’s own descendants instead of letting it lapse. Under the Uniform Probate Code’s version, if the beneficiary who failed to survive was a grandparent, a descendant of a grandparent, or a stepchild of the testator, the gift passes to that beneficiary’s surviving descendants.
So if a father leaves money to his daughter and they both die in the same accident, the daughter’s children can step into her place and take the gift, even though they were never named. Anti-lapse statutes don’t cover every relationship, and a will can override them with explicit language like “only if my daughter survives me.” But when they apply, they change who ends up with the property, and many families don’t learn these statutes exist until the question comes up.
Proving Who Died When
The whole framework depends on knowing when each person died. Death certificates are the starting point, and when they list a specific date and time, the paperwork usually settles the question.
Trouble arises when a certificate shows only a date, or when the time is an estimate rather than an observed moment. Hospital records, paramedic logs, and nursing notes can fill the gaps by documenting when vital signs were last observed or when resuscitation ended. Coroner and medical examiner reports add detail about the body at discovery, which helps estimate time of death when no one witnessed it. In contested cases, forensic pathologists may testify about biological markers to establish a timeline. Getting records quickly matters, because hospitals and emergency services don’t retain detailed logs forever, and once that data is gone, a 120-hour showing may be impossible.
Writing Your Own Survivorship Clause
The 120-hour rule is a default, not a ceiling. You can match it, extend it, or eliminate it in your own documents, and many estate planners recommend putting an explicit clause in the will or trust so there’s no ambiguity about what you intended.
- Restating the 120-hour requirement so it appears on the face of the document.
- Extending the period to 30 or 45 days, which gives a wider buffer and is common in plans for married couples with overlapping beneficiary lists.
- Eliminating the requirement, so a beneficiary inherits regardless of how long they survive. This can make sense when you want the property to follow a specific path no matter what.
Married couples have a tax ceiling to watch. A survivorship clause creates a “terminable interest” that can disqualify a bequest from the federal estate tax marital deduction, but federal law carves out an exception as long as the required survival period does not exceed six months and the spouse does in fact survive that period. The default 120 hours sits well inside that limit. A seven-month clause does not, and for a large estate it could cost hundreds of thousands in lost deductions. Most planners cap spousal survivorship clauses at 30 to 90 days to stay safely under the line.2Office of the Law Revision Counsel. 26 USC 2056 – Bequests, Etc., to Surviving Spouse
Beneficiary designations on life insurance, IRAs, and other accounts deserve the same attention. These forms, not the will, control who receives the asset, so name a contingent beneficiary and, where the form allows it, state a survivorship period. A carefully drafted will will not fix a beneficiary form that still names someone with no backup.