Balotelli, 25, arrived in Milan early on Tuesday to finalise a move back to San Siro from Anfield for the 2015-16 campaign, and both clubs have now confirmed the deal.
Speaking to reporters outside the La Madonnina clinic before the deal was concluded, the Italy international said: “I’m happy to be back.
“I’m fit, I just need to train with my team-mates. I don’t want want to talk too much, I’m only focused on working hard because I want to have a good season.”
The 25-year-old will spend the duration of 2015-16 with the Serie A outfit.
Balotelli made 28 appearances for the Reds in the previous campaign following a move to Anfield from Milan last August.