barry17 – https://airlinesbuddy.com/frontier-airlines-san-juan-airport-terminal-sju/

Frontier Airlines does operate flights to San Juan, Puerto Rico. Frontier Airlines offers nonstop flights to San Juan from several cities in the United States, including Miami, Orlando, Philadelphia, and Raleigh/Durham. The exact flight schedules and routes may vary, so it is best to check Frontier Airlines’ website or contact their customer service for the most up-to-date information.