The Unified Medical Language System (UMLS) integrates many well-established biomedical terminologies. The UMLS's semantic network (SN) can help orient users to the vast knowledge content of the Metathesaurus via its abstract conceptual view. However, the SN itself is large and complex, and may still be difficult to comprehend. Our technique partitions the SN into even higher-level abstract entities which are amenable to display on limited-sized computer screens. The basis for the partitioning is the distribution of the relationships within the SN. The results of applying our technique to the UMLS are discussed.