In 1950 Bach became one of the nation's youngest head coaches at a major college when he took over the coaching job at Fordham. He spent 18 years there, taking seven Ram teams to post-season tourneys, before starting a long and successful coaching career at Penn State, where he joined three old friends from Brown; Rip Engle, Joe Paterno and Joe McMullen. Bach would later coach the Golden State Warriors for three years. He served as an interim coach in 1980, and then as the full-time coach from 1983 to 1986. In 1986 Bach joined the Chicago Bulls as an assistant. After the team won three championships from 1991 to 1993, Bach moved on to coaching jobs with the Charlotte Hornets, Detroit Pistons and Washington Wizards. He returned to the Bulls in 2003, and retired in 2006.
After retiring from basketball, Bach turned to painting. In 2007, thirty-two of his watercolors were put on display at the Sevan Gallery in Skokie, Illinois. Bach died on January 18, 2016 in Chicago, Illinois at the age of 91. Bach's funeral was held two days later on January 20, 2016 at the Old St. Patrick's Church in Chicago. 
National champion Postseason invitational champion Conference regular season champion Conference regular season and conference tournament champion Division regular season champion Division regular season and conference tournament champion Conference tournament champion