"Excited to announce that I will be coming back to [Germany] for the Mercedes Cup," he said in an announcement on Facebook. "Looking forward to seeing you at the grass courts in Stuttgart."
It is the same schedule Federer followed in 2017, again not playing on clay and then competing at three grass-court events. But he got off to a shaky start, falling to Tommy Haas in his opening round at Stuttgart before rebounding to capture Halle and Wimbledon.
Other players scheduled to compete include defending champion Lucas Pouille, finalist Feliciano Lopez, Milos Raonic, Nick Kyrgios and Hyeon Chung.
Federer is No. 2 in the rankings.