All of NY 30A north of NY 7 in Central Bridge was originally designated as New York State Route 148 as part of the 1930 renumbering of state highways in New York, replacing NY 54 from Fonda to Mayfield. The piece of modern NY 30A south of NY 7 has been part of several routes, namely NY 30 from 1930 to the 1940s and NY 43 during the 1920s and from the 1940s to the 1950s. In April 1960, this piece of NY 43 was combined with NY 148 to create NY 30A.