Originally Posted by
sjmoss23
Could this be a M fare? I'm 1K and get an upgrade on M fares if it is available. I was offered this on EWR-DFW the other day and I calculated the buy-up and it was exactly the difference between my H fare and M fare.
If the OP was searching for flights via the website (I'm reading the plotting they did as such) then an M-fare would still show as United Economy on the search results page (with the Premier 1K Instant Upgrade symbol visible). It isn't uncommon to see A or even F fares show up on that page when searching for economy on close in flights.