National Library of Medicine is a participant in the CONSER Program, a cooperative effort by the North American library community to build a machine-readable database of serials cataloging information. CONSER records are entered in the OCLC Online Union catalog (OCLC-OLUC) according to CONSER conventions, one of which is to have serials represented by only one cataloging record with no duplicate records. At this time NLM serial cataloging data must be added to the OCLC OLUC file manually because of CONSER conventions and OCLC system constraints. NLM also changes CONSER records to indicate that serials have been selected or deselected for indexing by services supported by NLM: Index Medicus, Hospital Literature index, Index to Dental Literature, or International Nursing Index. The purpose of this project is to ensure that: a) for each serial cataloged by NLM a record will exist in the CONSER file which complies with the CONSER conventions and standards; b) existing OCLC OLUC records for serials related to those cataloged have been modified to show linking relationships; and c) OCLC serial records reflect indexing coverage. In 1995, the base period of a planned three year contract project, contractor support is necessary to enter data into the OCLC OLUC for up to 1,495 serials cataloged, modify approximately 400 records to show linking relationships, and add indexing notes to approximately 200 records.