The Pennsylvania Union List of Serials (PaULS) is presently in the process of transition from development to maintenance. Since October 1, 1979, its development has been supported by the State Library of Pennsylvania with LSCA funds. The current article describes accomplishments of PaULS from early 1981 through April 1983 including the production of its “core titles” in COM fiche and the conversion of its records by OCLC to the format required for the union listing capability. Current and future problems for PaULS are discussed as are long-term maintenance issues. In addition, PaULS’ role as one part of the national serials database is examined.