Maintaining value sets is a necessary and distinct activity apart from maintaining recognized controlled vocabularies. As an illustration of one such value set, we evaluate the CDC and Regenstrief versions of the notifiable condition mapping tables (NCMT) and illustrate they are not synchronized. We used practical informatics approaches including heuristic queries and similarity measures to accurately identify more than 800 new candidate reportable LOINC codes. To successfully maintain value sets we must establish a clear strategy for coordinating the value sets and process for disseminating among stakeholders. These stakeholders will likely be distinct from, but interface with, the existing standards development organizations (SDOs).