He also worked in Orchestra USA and participated on Benny Carter's Further Definitions album, and worked on some of Helen Merrill's recordings.
In the late 1960s, he played with Roy Eldridge and Lee Konitz.
In the 1990s, he worked as a pianist and arranger with the American Jazz Orchestra and Loren Schoenberg's big band.
Will Friedwald called Katz "a keyboardist of uncommon sensitivity and harmonic acumen." He was the favorite pianist of Benny Carter and Coleman Hawkins, as well as vocalists Carmen McRae and Helen Merrill.