Who’s your father for inheritance purposes in California? Family Code section 7540(a) states that “the child of spouses who cohabited at the time of conception and birth is conclusively presumed to be a child of the marriage.” A child covered by this marital presumption is not an heir of a deceased third person even if genetic testing proves a parent-child relationship.

In Estate of Franco (2023) 87 Cal.App.5th 1270, the Court of Appeal clarified that, in order for the marital presumption to be applied, there must be a clear showing of cohabitation (living together) at the time of conception and birth.