Denied boarding? Before you accept or sign anything at the gate, establish whether it was voluntary or involuntary. If the airline told you that you are not boarding, that is involuntary denied boarding, and a federally mandated cash payment can apply - ask for cash, not a voucher, and a confirmed seat.
Involuntary denied boarding is the one disruption where US law is unambiguously on your side - and the one where travelers most often accept far less than they are owed, because a voucher offered at the gate sounds generous in the moment.
Do several things at once. Get in the line, and call the airline, and open the app - whichever connects first wins. Standing in one line doing nothing else is how travelers lose four hours and every good seat.
Facts reviewed August 2026. General guidance, not legal advice.