start against the Cleveland Indians, Gausman threw the 90th immaculate inning in MLB history, striking out three batters in one inning on just nine pitches. Atlanta Braves On July 31, 2018, Gausman along with Darren O'Day, was traded to the Atlanta Braves in exchange for minor leaguers Brett Cumberland, Jean Carlos Encarnacion, Evan Phillips, Bruce Zimmermann, and international signing money. During spring training in 2019, Gausman dealt with a sore shoulder. He began the season rehabilitating in the minor leagues, and made his season debut on April 5. On May 3, 2019, Gausman was ejected from a game against the Miami Marlins by umpire Jeff Nelson for throwing behind José Ureña. He and Ureña had last faced each other on August 15, 2018, when Ureña hit the Braves' Ronald Acuña with a pitch. Major League Baseball fined and suspended Gausman for five games. Gausman initially appealed the suspension. On May 12, Gausman dropped his appeal. In 16 starts, he was 3–7 with a career-high 6.19 ERA. and struck out 85 batters in 80 innings. Cincinnati Reds On August 5, 2019, the Cincinnati Reds claimed Gausman off waivers from the Braves. With the Reds, Gausman became a reliever. In a relief appearance against the St. Louis Cardinals on August 18, Gausman struck out all six batters he faced, including tossing his second career immaculate inning. In 2019 with Cincinnati he was 0–2 with a 4.03 ERA in 15 games (one start) in which he threw innings, walked five batters, and struck out 29 batters. Gausman was non-tendered on December 2, 2019, and became a free agent. San Francisco Giants 2020 season On December 10, 2019, Gausman signed a one-year $9 million contract with the San Francisco Giants. During the shortened 2020 season, Gausman had a major bounce-back season, in which he was 3–3 with a 3.62 ERA and 15 walks and 79 strikeouts in innings in 12 games (10 starts), and a career-low 1.106 WHIP along with a career-high 11.9 K/9. On November 11, 2020, Gausman accepted a qualifying $18.9 million offer from the Giants. 2021 season Gausman was the 2021 Opening Day starter for the Giants. He was named the National League Pitcher of the Month for the month of May 2021. He won five games during the month, maintained an ERA of 0.73, and allowed an opponent slash line of .165/.201/.241. He was a 2021 National League All Star.