The Giants signed Oates in 1985 at the relatively advanced age of 26. This was because he had initially played three seasons with the Philadelphia/Baltimore Stars in the USFL where he won two USFL championships. Oates has stated that he feels the 1985 Philadelphia Stars of the USFL could have beaten the 1985 Philadelphia Eagles. Oates won three Super BowlGiants in 1986 and 1990, and one with the 49ers in 1994. Oates was selected to five Pro Bowls during his career and to the UPI All-NFC team three times. He was extremely durable, starting 125 consecutive games during his Giants career.
Oates is currently the President of the NFL Alumni Association with primary missions of Caring for Our Own and Caring for Kids. He attended law school classes during the off-season of football and graduated magna cum laude with a Juris Doctor degree from Seton Hall Law School in 1990. He worked with the law firm of Ribis Graham and Curtin in Morristown NJ and Raymond Koski and Associates in Fort Lee NJ and the real estate company Gale and Wentworth in Florham Park NJ. His primary focus of practice was real estate and health care. He is also a member of the New Jersey State Bar Association. He was chairman of the New Jersey Hall of Fame, a Hall of Fame for New Jersey residents in a variety of fields ranging from scientists to athletes. He was selected to be inducted into the New Jersey Hall of Fame Class of 2019. In 2006 Oates voiced himself in the Aqua Teen Hunger Force episode "Bart Oates." He also spent time helping out as the line coach at Seton Hall Preparatory School earlier in the decade. He currently serves as the Bishop (lay Pastor) of the Morristown NJ 1st Ward of the Church of Jesus Christ of Latter Day Saints.
Oates and his wife, Michelle, have three children and currently reside in Harding Township, New Jersey. Oates' brother, Brad, also played offensive line in the NFL for six seasons on five different teams.