California Family Code
Family Code section 7540
CHAPTER 1. Child of Wife Cohabiting With Husband [7540 - 7541]
( Chapter 1 heading added by Stats. 1993, Ch. 219, Sec. 172. )
7540.
Except as provided in Section 7541, the child of a wife cohabiting with her husband, who is not impotent or sterile, is conclusively presumed to be a child of the marriage.