It was one of the most successful models of the Universal Series, with 481 units built, including 16 exported to Peru.

The Georgia Central as of July 2015 has all of its U23Bs off of the roster with the 3965 going to the Southern Appalachia Railway Museum in Oak Ridge, TN.

The last U23B built, originally Conrail 2798, and more recently Providence and Worcester 2203, is in regular freight service at the Naugatuck Railroad in Thomaston, Connecticut.

Western Rail Inc in Airway Heights, WA currently has a U23B that is leased out to other railroads.

RJ Corman operates at least one, Road Number 2300, after acquiring the Lehigh Railway short line in Northeast Pennsylvania.