Murray missed five months of the ATP Tour this season after undergoing hip resurfacing surgery in January following his Australian Open first-round defeat to Roberto Bautista Agut. Despite suggesting his appearance in Melbourne could have been his last professional match, Murray returned from a successful operation at the Queen's Club Championships ahead of Wimbledon.
There, Murray was crowned doubles champion alongside Feliciano Lopez -- who also won in the single's draw -- but the Scot had mixed success this month at the All England Club.
Murray's return to the Citi Open comes as a surprise due to his clash with tournament director Keely O'Brien last year. The Scot broke down in tears after earning an emotional victory against Marius Copil at 3 a.m. in Washington, and then elected not to play his quarterfinal later that same day, to the frustration of O'Brien.
The tournament director said at the time: "I hope that Andy takes into consideration this role in his sport, and as a global role model to guys and girls on the tour and kids around the world.
"When things are difficult and tough and the conditions aren't great, it's not OK to just give up."
When asked earlier this year if he would return to the Citi Open, Murray replied: "Probably not after the tournament director rinsed me."
Jamie Murray won the doubles final in Washington last year with then-partner Bruno Soares, and has won two doubles titles with Andy.