Availability of upgrade seats depends on demand for full-fare premium cabin tickets. As a result, upgrades may not be available for every flight. Keep in mind that many premium cabin bookings do not occur until a week or two before departure, so upgrades may not become available until as late as the day of departure.

If an upgrade is not available at the time of your request, you will be placed on a waiting list. If upgrade seats become available, they will be assigned based on MileagePlus status and booking class, so those factors will also affect your likelihood of receiving an upgrade.

To find out if you have received an upgrade, you can check the status of your request through My My Itineraries.