With the Dodgers, Oates worked as a second-string catcher behind Steve Yeager and, would once again reach the post-season as, the Dodgers clinched the 1977 National League West title. The Dodgers went on to defeat the Philadelphia Phillies in the 1977 National League Championship Series before eventually losing to the New York Yankees in the 1977 World Series. In 1978, Oates appeared in only 40 games as the Dodgers repeated as Western Division champions and, once again defeated the Philadelphia Phillies in the 1978 National League Championship Series. The 1978 World Series was also a repeat of the previous year as, the Dodgers once again lost to the Yankees in a six-game series. Oates' playing time decreased further in 1979 as he appeared in only 26 games before being released at the end of the season. He became a free agent and signed a contract to play for the New York Yankees on April 4, 1980. Oates served as a backup to Rick Cerone during the 1980 season before playing in his final game on May 24, 1981, at the age of 35.