RxNorm Marks Its 20th Anniversary

RxNorm, the National Library of Medicine’s standardized nomenclature for clinical drugs, marks its 20th anniversary this year. First distributed as a standalone full monthly release in 2005, RxNorm was developed to provide normalized drug names (active ingredient + strength + dose form) and unique identifiers (RxCUIs) that enable consistent representation of medications across electronic health systems. It provides links from clinical drugs, both branded and generic, to their active ingredients, drug components (active ingredient + strength), and related brand names. The December 2025 edition of RxNorm includes 14,592 (base) ingredients, 5,151 brand names, 17,544 clinical drugs, 9,721 branded drugs, 645 generic packs, and 747 branded backs.

Over the past two decades, RxNorm has become an essential component of health information exchange in the United States. It supports interoperability among electronic health records (EHR), e-prescribing systems, clinical decision support tools, and research platforms. RxNorm plays a central role in the U.S. Core Data for Interoperability (USCDI), where it is designated as the standard for representing medication information in nationwide data exchange. RxNorm’s monthly releases provide updated drug products, dose forms, and clinical drug concepts, ensuring that the terminology remains current with changes in the marketplace and clinical practice. The RxNorm files are downloaded about 1,000 times each quarter, and the RxNorm API serves 4 billion queries annually. Usage of RxNorm has increased markedly over the past decade.

RxNorm links its normalized drug names to many of the drug vocabularies commonly used in pharmacy management and drug interaction systems, including those maintained by major terminology vendors that support electronic health record systems. As part of the Unified Medical Language System (UMLS), RxNorm links medication concepts across multiple terminologies and coding standards, including those that are not primarily focused on medication information. By providing links between these vocabularies, RxNorm can facilitate communication between systems that do not use the same software and vocabulary. Learn more about RxNorm.

As RxNorm reaches its 20-year milestone, it continues to advance NIH’s broader goals of developing accurate, consistent, and interoperable health data standards, improving data sharing, and enabling integration of various data sources for research and clinical use.