Originally Posted by lindaiah

I've got a flight booked (four segments/two each way) where one of the segments is "Ineligible to accrue mileage or Premier qualifying credit."
Fare class is "United Economy K" (same as two of the other segments that are eligible for mileage and PQ credit), operated by Skywest Airlines "DBA United Express" (flight number is UA+four digits, starting with a 5), all other flights are also UAxxxx, and the ticket number is "016xxxxx...."

Why would this one segment be ineligible to accrue mileage or PQ credit?