When it comes to the California Family Code, there are two different marital presumptions parents should be aware of. Family Code §7540 addresses the conclusive marital presumption, which provides that a husband is conclusively presumed to be the father of a child born to his wife, as long as the husband and wife were cohabiting at the time of conception and the husband is neither impotent nor sterile.
The result of this presumption is to codify the principle that if a husband could be the father, and the husband wants to be the father, the husband will legally be the father regardless of actual paternity. Generally, a man other than the husband does not have standing to request an order for genetic testing. Family Code §7541
Family Code §7511, subdivision (a), addresses the rebuttable marital presumption. Yet, be aware the California Supreme Court has made it clear that California will defend marital families from outside interference to the extent the husband is functioning as the child’s parent.