The Red Devils signed Young from Aston Villa back in 2011 and the England international has gone on to make over 250 appearances for the club.
Young has played crucial roles in Trophies won by United over the years with the FA Cup under Louis Van Gaal, the Europa League and EFL Cup Trophies under Jose Mourinho.
According to ESPN, Talks over a new contract for Young has not taken place and he is now set to leave for free at the end of the season.
The Red Devils transformed Young from a Winger to a right-back over the years and there are now enough options for that position.
Young is still United's captain and despite his ability to play from both defensive wings, his playing time has been reduced dramatically by Aaron Wan-Bissaka, Dalot, Luke Shaw and Brandon Williams.
United offered young a one-year contract at the end of last season and that appears to be his final deal at the club.
Young is now free to speak to clubs and negotiate in January about his next transfer move.
Manchester United are expected to be very busy in the January transfer window with a lot of players being linked already.
Speaking about transfer plans, Coach Ole Gunnar Solksjaer said:
"We are looking at strengthening the squad in various positions.
"If you compare our squad with others, you had see that we’re getting there, but still need some new additions like two or three players to have a stronger squad with enough options to rotate throughout a long campaign and we will see who we can sign."