Manchester United were 19 points behind then league leaders Liverpool when Mourinho was sacked as manager
Manchester United paid Jose Mourinho and his staff £19.6m in compensation following his sacking in December.
United revealed the figures in their second quarter financial results.
Mourinho was sacked after a run of poor results, culminating in a 3-1 defeat by Liverpool, that left them 11 points off fourth place in the Premier League.
Caretaker manager Ole Gunnar Solskjaer won 10 of his first 11 games before Tuesday's 2-0 Champions League last-16 first-leg defeat by Paris St-Germain.
Within the financial results, which were released to the New York Stock Exchange, it said: "Exceptional items for the quarter were £19.6m, relating to compensation to the former manager and certain members of the coaching staff for loss of office."
Mourinho, 55, took over in May 2016 and led United to League Cup and Europa League titles. In January 2018 he signed a contract extension until 2020 with the option of an extra year.
United executive vice-chairman Ed Woodward says Solskjaer's appointment, along with that of Sir Alex Ferguson's former coach Mike Phelan as his assistant has "had a positive impact throughout the club".
"Ole has made a fantastic start reviving performance of team," Woodward said.
Woodward says he thinks United, who have reached the fifth round of the FA Cup and are now fourth in the Premier League, above Chelsea and Arsenal, will now have "a strong finish to the season".
He refused to offer any update on Solskjaer's future, insisting the club will stick to its plan of offering an update at the end of the season.
When asked about recruiting for a director of football role, he said: "Looking at our structures and how we should strengthen all areas at the club is something we do on a continual basis. We have invested on the player care side. The evolution is continuing but it is not necessarily visual. We are looking at ways we can make the structures stronger."
