NY 54 was reassigned elsewhere in the state as part of the 1930 renumbering of state highways in New York. The portion of NY 54's former alignment south of Mayfield became part of NY 148, a new route that extended from NY 7 in Central Bridge to NY 30 in Mayfield. The section of modern NY 30A south of NY 7 was initially designated as part of NY 43 in the mid-1920s before becoming part of NY 30 in 1930. In the early 1940s, NY 30 was rerouted to follow a new highway that left the old alignment of NY 30 southeast of Central Bridge and connected directly to the portion of NY 30 north of NY 7. The former routing of NY 30 into Central Bridge became an extension of NY 43, which overlapped NY 30 between the new alignment and Schoharie.