 Pfeiffer served as executive assistant to the New York State Comptroller from 1943 to 1946, and was Deputy Comptroller from 1946 to 1948.In 1948 Pfeiffer ran successfully for a seat in the United States House of Representatives.He served in the 81st Congress, January 3, 1949 to January 3, 1951, and was not a candidate for renomination in 1950.