It's the latest attempt by airlines to increase revenue during a normally slow time of year for travel. They succeeded in raising prices two weeks ago, but another fare hike last week fizzled and was eventually canceled.
US Airways confirmed Thursday that it had raised fares by $4 to $10 per round trip.
American says it's considering whether to match the increase. Southwest and JetBlue say they haven't matched it yet either, and other airlines didn't immediately comment.
Airlines have tried about 20 fare hikes this year, with half sticking. The others were rolled back, usually because some airlines declined to go along.