Originally Posted by bse118

EXP's are eligible for upgrades on award tickets on flights where the complimentary/500 mile upgrade system is in place (essentially shorthaul). JFK-MXP (or any other international longhaul) is not included.

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That said - EXPs do get access to Premium Economy seats with 24 hours of departure, if any are available, and the system is behaving itself. I've not seen any reports of information about if this works on award tickets or not. Would be curious to know.