In 2019, he was 6–5 with 29 saves (6th in the NL) and a 4.05 ERA, as in 63 relief appearances he pitched 60 innings and struck out 66 batters. He led the NL in games finished (55), powering his Nationals to a World Series appearance and a save in Game 1. In innings during the postseason, he gave up only two runs and six hits while striking out eight.