Plan on two hours before departure
For most domestic flights in the U.S., aim to reach the airport two hours before scheduled departure. That gives you time for check-in or bag drop, security, and the trip to your gate. TSA and major airports recommend allowing time for the full process.
Allow for the parts of the trip before security
You may need less time if you’re checked in, traveling with carry-on luggage, and heading to a nearby gate. But that leaves less room for a security line or a long walk or train ride, so treat a shorter window as an estimate, not a guarantee.
Start with the two-hour baseline and add time for checked bags, children, a large or unfamiliar airport, or a busy travel period. Remote parking, rental-car returns, and shuttle waits all happen before you reach the terminal. Live checkpoint estimates can help you gauge the security line, but they don’t account for bag drop or the rest of the trip from curb to gate.
Reach the gate by your boarding time
Your airport arrival target and your airline’s check-in or bag-drop cutoff are different deadlines. Cutoffs vary by airline and flight, and boarding or gate closure takes place before scheduled departure. Check your airline’s current requirements, and use the boarding time in your travel details as your target for reaching the gate.
One traveler reported arriving at American Airlines bag drop at Columbia Metropolitan Airport 42 minutes before departure, three minutes past the cutoff they cited. They said the system would not issue a bag tag. That single report doesn’t establish how every airport handles late bags; it does show why a cutoff is a deadline, not an arrival target.