Originally Posted by jkBosman

Hi,
Did some searching around but couldn't find any answers to this.

I am a Mosaic looking at a BOS-LAX flight later this year. The flight options using the new AA codeshare are significantly cheaper. However I notice that it gives me the message that no seat selection is available on the flight if I try to book one of these via jetblue.com.

1) Will I be able to upgrade to a Main Cabin Extra seat (this seems to be AA equivalent of EMS), either via cash or points? Will I even be able to select seats at all in advance?

2) Will any other Mosaic benefits be usable on an AA codeshare flight?

Thanks, appreciate the insight if anyone has had the chance to book any of these flights thus far. I am not enthusiastic about a transcon in regular economy with AA's 31" pitch, so I'm hoping that I can upgrade/select better seats.