The news was made public in the tech giant's annual proxy filing on Thursday, and comes as a group of activist investors, believed to hold more than a 5% share of the company, call for a re-invigoration in the face of tough competition from Google and Apple.
Ballmer, 57, said back in August that he would be retiring in 12 months, but it's expected the new CEO will continue the current direction dictated by the board.
Meanwhile company co-founder Gates is expected to stay on as Chairman of the board, angering investors who, as we reported earlier this week, called for him to step down for the good of the company.
The annual shareholders meeting will be held on 19 November and it's expected both men will be re-elected.
Microsoft has had a tough few years due to questions around its Xbox and smartphone strategies, but Microsoft remains one of the world's most valuable technology companies with a net profit of US$22 billion last fiscal year.
The company is still hunting a replacement CEO for Ballmer, and it's unclear if Ballmer will remain on the Microsoft board, as Gates has, once a replacement has been anointed.