In most cases, married couples own their stuff jointly with the right of survivorship. That means when one spouse dies, the other is now the sole legal owner of everything they owned together. Every state prohibits totally disinheriting a surviving spouse (unless a couple has signed a prenuptial or postnuptial agreement). That rule covers most situations, but here are some examples of how a spouse be able to leave property to someone other than the surviving spouse:
The dead spouse’s will (only if there’s a signed prenuptial or postnuptial agreement)
Any trusts the decedent put in place
Transfer-on-death accounts (like stocks, bonds or retirement accounts) where assets go straight to a specific beneficiary