1,123. Who Need Not Redeem Their Sons?

164:8 If the father ignored his obligation and didn't redeem his son, or if he died and the beis din didn't redeem the baby, then the son is obligated to redeem himself when he becomes an adult. He recites the bracha "...Who sanctified us with His commandments and commanded us regarding the redemption of a first-born" and Shehechiyanu.

164:9 Kohanim and Leviim are exempt from redeeming their sons. Even if the daughter of a kohein or a Levi marries an Israelite, her son is exempt from redemption. If the daughter of a kohein became pregnant from a non-Jewish man, or even if she became pregnant from a Jewish man after previous relations with a non-Jewish man, the son must be redeemed because his mother is no longer treated as a kohein's daughter in halacha. The same is true with any other forbidden relationship that causes her to lose priestly status.