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RxNorm Terms of Service


The full RxNorm dataset includes government-created and proprietary names and codes for clinical drugs. A free UMLS license is required to download the full RxNorm monthly and weekly releases.

The RxNorm terminology normalized names and codes (e.g. RXCUI) within the RxNorm dataset is created by the National Library of Medicine (NLM) and is in the public domain as it is created by the U.S. government. Public domain information may be freely distributed and copied within and outside the U.S., but it is requested that in any subsequent use, NLM be given appropriate acknowledgement.

The full RxNorm dataset includes proprietary data from various terminology providers, each with a specific Source Restriction Level (SRL) category. Section 12 of the Unified Medical Language System (UMLS) license agreement describes the categories and specific restrictions on how a terminology can be used.

Contact the terminology source data provider directly to discuss uses of a terminology beyond those allowed under the UMLS license agreement and possible costs. Contact information is available on a specific source terminology page, under the “Metadata” tab, which can be accessed from the RxNorm Source Vocabularies list.


  • A free UMLS License is required to download the full RxNorm releases.
  • We request that any product that makes use of RxNorm data include the following statement:
    "This product uses publicly available data courtesy of the U.S. National Library of Medicine (NLM), National Institutes of Health, Department of Health and Human Services; NLM is not responsible for the product and does not endorse or recommend this or any other product."
  • If you use RxNorm in your work, please cite:
    Nelson SJ, Zeng K, Kilbourne J, Powell T, Moore R. Normalized names for clinical drugs: RxNorm at 6 years. J Am Med Inform Assoc. 2011 Jul-Aug;18(4)441-8. doi: 10.1136/amiajnl-2011-000116. Epub 2011 Apr 21. PubMed PMID: 21515544; PubMed Central PMCID: PMC3128404.

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  • Developers may not use the NLM name and/or logo in conjunction with their applications.
  • Users of the data agree to not indicate or imply that NLM has endorsed its products/services/applications.
  • Users who republish or redistribute the data (services, products or raw data) agree to:
    • maintain the most current version of all distributed data, or
    • make known in a clear and conspicuous manner that the products/services/applications do not reflect the most current/accurate data available from NLM.
  • NLM does not provide legal advice regarding copyright, fair use, or other aspects of intellectual property rights. See the NLM Copyright page.
  • NLM reserves the right to change the type and format of its machine-readable data. NLM will take reasonable steps to inform users of any changes to the format of the data before the data are distributed via the RXNORM-ANNOUNCES-L page.
  • DISCLAIMER: It is not the intention of NLM to provide specific medical advice, but rather to provide users with information to better understand their health and their medications. NLM urges you to consult with a qualified physician for medical advice.
  • See the NLM Terms and Conditions for additional clauses.

Last Reviewed: January 31, 2022