Uniform Simultaneous Death Act

The Uniform Simultaneous Death Act is a model law adopted by U.S. states that determines how assets are distributed when two people, typically a married couple, die in the same accident or close enough together in time that it is impossible to determine who died first. Without this law, a court might face an impossible question: does the husband's estate inherit from the wife, or vice versa? The Act resolves that question by treating each person as having predeceased the other for purposes of their respective estate, unless one person survived the other by at least 120 hours.

Think of it as a legal tiebreaker that prevents estate assets from ping-ponging uselessly between two people who both died in the same event.

The 120-Hour Survival Requirement

The 1993 revision of the Act, which most states have adopted, requires a beneficiary to survive a decedent by at least 120 hours, or five full days, to inherit. If two spouses die in a car accident and one survives the other by only two days, that survivor is treated legally as having predeceased the other. Each person's estate then passes as if they had died first, going to their respective alternate beneficiaries, heirs, or contingent beneficiaries.

This rule prevents assets from transferring twice in rapid succession through two estates, generating double probate costs, double estate administration fees, and potential double estate tax exposure when the surviving spouse's estate is large.

How It Applies to Specific Asset Types

The Act's application varies slightly depending on the type of asset at stake.

• Wills: A bequest in a will fails if the beneficiary does not survive the testator by 120 hours. The bequest then passes to the alternate or residual beneficiary named in the will.
• Life insurance: If the named beneficiary dies simultaneously with the insured, the policy proceeds pass to the contingent beneficiary rather than flowing through the beneficiary's estate. If no contingent beneficiary is named, the proceeds become part of the insured's estate.
• Joint tenancy property: When joint tenants die simultaneously, the Act treats the property as if both had died at the same moment, splitting it into equal shares that each pass through their respective estates rather than triggering the survivorship right that normally makes joint tenancy property pass automatically to the survivor.
• Trusts: A trust beneficiary who fails to survive the grantor by 120 hours is treated as having predeceased, triggering whatever alternate distribution the trust document specifies.

Why the 120-Hour Rule Replaced the Old Rule

The original 1940 version of the Act simply provided that when deaths were simultaneous and the order could not be determined, each person was treated as having predeceased the other. The 1993 revision extended this to require 120 hours of survival rather than mere simultaneous death, because modern medical technology frequently keeps trauma victims alive for days in intensive care, making the old "who died first" determination technically answerable but practically meaningless in terms of estate planning.

A spouse who survives a car accident by four days but never regains consciousness and ultimately succumbs to injuries is not meaningfully a survivor for purposes of inheriting and managing an estate. The 120-hour rule prevents that technical survival from triggering an estate transfer that the decedent did not intend.

How to Account for This in Estate Planning

The practical implication is that every estate plan should name contingent beneficiaries for every asset that passes by beneficiary designation, including life insurance policies, retirement accounts, and transfer-on-death accounts. You should also include a survival clause in your will specifying that a beneficiary must survive you by at least 120 hours, or longer if you prefer, to inherit under the will. Many estate attorneys recommend a 30-day or 60-day survival period in wills to prevent assets from flowing into a co-beneficiary's estate and creating a second round of probate.

Sources

• https://www.uniformlaws.org/committees/community-home?CommunityKey=a3420e37-2e69-4cf5-9e6e-3e0697e13b38
• https://www.law.cornell.edu/uniform/vol8#simu