In college football, Lewis was one of the top cornerbacks to ever play at Pittsburgh, making NEA All-American in 1982, as well as being the Defensive MVP of the 1982 Senior Bowl and East-West Shrine Game. He was drafted in the first round by Green Bay as the 11th overall and first cornerback pick of 1983. He was their starting quarterback till neck injury ended his playing career early in the 1986 season. He had 16 career interceptions in just over 3 seasons at Green Bay.

In 1987 Tim became an assistant at Texas A&M, then moved on to Southern Methodist where he was the defensive backs coach from 1989 to 1992. He took advantage of an opportunity to return to the University of Pittsburgh as the DB coach in 1993, where he remained for another year. The Steelers then hired him as their DB coach in 1995.