He was signed by Louis van Gaal in 2015 and started well but then struggled with fitness and form.
He failed to make a Premier League appearance this season but did come back into the squad and played in three games in 2017.
Bastian Schweinsteiger is on his way to Chicago to join the Fire
Bastian Schweinsteiger could make his Chicago debut on Saturday
Man Utd fans reacts as Bastian Schweinsteiger signs for Chicago Fire
Tue, March 21, 2017
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Schweinsteiger played 90 minutes, scored and got an assist in the FA Cup against Wigan at the end of January.
But it announced he would be joining the MLS side last week and today his clearance has gone through.
The 32-year-old posted a picture with his wife Ana Ivanovic as they boarded a flight to the States.
“On my way to Chicago with @anaivanovic!” read the caption on Instagram.
A post shared by Bastian Schweinsteiger (@bastianschweinsteiger) on Mar 28, 2017 at 7:40am PDT
The World Cup winner could be unveiled this week and make his debut against Montreal Impact on Saturday.
The Fire have won one, drawn one and lost one of their three games so far and sit seventh in the Eastern Conference.