No. Puerto Rico is a U.S. territory, so a flight between SJU and any U.S. mainland airport is domestic travel — you need REAL ID (or a passport) the same as any other domestic flight, and Puerto Rico is listed alongside the 50 states in TSA’s own REAL ID guidance. Passport checks at SJU are only for travelers arriving on an international flight, who go through U.S. Customs and Border Protection’s facial-biometric Simplified Arrival process at the primary inspection point.