Under UEFA regulations, any European team that spends more than its generated revenue faces possible sanctions, including, with a ban from playing.
However teams are able to ask for a waiver to FFP rules under a so-called 'voluntary agreement' scheme, something Milan asked UEFA to exercise after Chinese entrepreneur Li Yonghong bought the club from Italian holding company Fininvest.
"There are still uncertainties in relation to the financing of the loans to be paid back in October 2018 and the financial guarantees provided by the main shareholder," UEFA said in a statement.
"AC Milan will continue to be subject to the ongoing monitoring process and the situation will be assessed again in the first months of 2018," it added.
Milan currently sit in seventh on the Serie A ladder, 16 points behind leaders Inter Milan, despite spending close to $300 million on players during the tranfer window, with notable additions including Italy defender Leonardo Bonucci and Portugal striker Andre Silva.