2,234. The Status of Kohanim Nowadays

Hilchos Issurei Biah 19:23

Let’s say that there is a suspicion that a person who may or may not be a chalal married into a particular family. In such a case, no widow from that family should marry a kohein but if she did so, they need not be separated because there’s a two-fold doubt: (1) maybe she’s the widow of that doubtful chalal and maybe she isn’t and (2) even if she is, maybe he was a chalal and maybe he wasn’t. However, if a man who was definitely a chalal married into a family, then every woman in that family is forbidden to marry a kohein until he investigates. If he marries without investigating, they must divorce. The same is true if a doubtful mamzer or a definite mamzer marries into a family. This is because the same prohibition applies to kohanim when it comes to the wife of a chalal and the wife of a mamzer, as was previously discussed.

Hilchos Issurei Biah 20:1

The priestly status of kohanim nowadays is based on a legal presumption. They may only eat sanctified food that is eaten within Israel so long as it’s trumah by rabbinic law. Trumah under Biblical law and challah under Biblical law may only be eaten by a kohein of confirmed lineage.