The Capitals say the procedure was done on Wednesday.
The team adds in a statement that ''according to the doctors who performed the surgery, if rehabilitation goes well, Eric will be healthy for the start of the 2015-16 regular season.''
Fehr had 19 goals and 14 assists in 75 games this past season. He missed 10 of the team's 14 playoff games because of injury.
The 29-year-old Fehr, who will be an unrestricted free agent this offseason, is the second Washington player to have surgery recently.
Center Nicklas Backstrom had hip surgery on May 27 and is expected to ready for next season.