Unified Medical Language System® (UMLS®) Basics

The UMLS Knowledge Source Server (UMLSKS)

The UMLS Knowledge Source Server (UMLSKS) provides Internet access to the three UMLS Knowledge Sources and to the UMLS tools. Users must log in to the UMLSKS with a Metathesaurus license number. The UMLSKS is supported but not maintained to be constantly available. Users should expect weekly downtimes for system enhancements.

One of the most important features of the UMLSKS is the ability to download all of the UMLS Release files. Users can access the newest release by downloading the files from the UMLSKS before the UMLS DVDs are produced. However, download times will be lengthy. After logging in to the UMLSKS follow the “UMLS Knowledge Sources” link under the title “Downloads” on the left hand side. The most recent release and a number of historic releases are available.