BrianCUnited

US and all of it's express partners are in *A until March 30, so any flight operated by US or one of it's express carriers will earn MP miles if flown on or before March 30. These flights have always earned MP miles. AA operated flights, even if they are US codeshares, have never (and will never) earned MP miles.

Also there is no such thing as a "Republic" flight for mileage earning purposes - this flight is marketed and sold as US Airways Express in this case which is why the MP webpages don't list it. If you bought an AA marketed and sold flight operated by Republic you would not earn MP miles. I can see how the language is a bit confusing but a US Airways "codeshare" operated by AA is different than a US Airways Express flight "operated' by Republic or Expressjet or any other regional carrier.

UA could make this easier to understand by excluding all US Airways flight numbers that are codeshares with AA from earning MP miles (I assume there's a standard range of flight numbers), but then how often are they actually "flyer-friendly" these days.

EDIT: I might be wrong that US codeshares on AA have a specific set of flight numbers. I looked through the schedule and can't tell just based on flight number whether the flight is operated by US or AA. Quite confusing for those of us who still want to credit to MP. I guess just pay close attention to operating carrier.