Whether 1.5 hours is enough at JFK depends entirely on the type of connection. If you are connecting Domestic to Domestic (e.g., Los Angeles to JFK to Boston) and staying within the same terminal (like Delta in Terminal 4 or JetBlue in Terminal 5), 1.5 hours is usually plenty of time. However, if you are arriving on an International flight and connecting to a Domestic one, 1.5 hours is highly risky and often impossible. You must clear immigration, collect your checked bags, pass through customs, re-check your bags, and clear TSA security again. For international arrivals, a minimum of 3 hours is recommended. Furthermore, if your connection requires changing terminals via the AirTrain, you must factor in an additional 20 to 30 minutes for transit and re-clearing security. In 2026, with JFK's ongoing terminal renovations, gate-to-gate walking times can be extensive, so 1.5 hours should be approached with caution unless you are flying on a single ticket with no terminal change.