> For the complete documentation index, see [llms.txt](https://docs.bcbi.brown.edu/codiac-for-health/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.bcbi.brown.edu/codiac-for-health/ursa-ri/datasets/national-plan-and-provider-enumeration-system-nppes.md).
# National Plan and Provider Enumeration System (NPPES)
## Overview
The National Plan and Provider Enumeration System (NPPES) is the national registry, operated by the Centers for Medicare & Medicaid Services (CMS), that assigns and maintains the National Provider Identifier (NPI) — the standard unique identifier for health care providers in the United States. Established under the Administrative Simplification provisions of HIPAA, NPPES enumerates both individual clinicians and provider organizations, each of which receives a single, permanent 10-digit NPI used to identify them in administrative and financial transactions such as claims, eligibility checks, and remittances. [\[1,5\]](#references) The system holds millions of active and deactivated records and functions as core infrastructure for the U.S. health care system, where the NPI serves as a common key for linking providers across enrollment, claims, and quality datasets.
## Methodology and Generation
The data are generated primarily through self-reported provider enumeration. A provider becomes part of NPPES by applying for an NPI and submitting the information that forms the core of its record. [\[2\]](#references)
Upon a successful application, NPPES generates and assigns a single 10-position, intelligence-free NPI. The identifier is assigned once, is permanent, and is not affected by later changes to name, address, or other fields; nor is it reused or reassigned to a different provider.5 Because the record is built from provider-supplied information, the database depends on providers to maintain their own data and to submit updates when their circumstances change. To keep provider enrollment and enumeration information aligned, NPPES is integrated with CMS's Provider Enrollment, Chain, and Ownership System (PECOS) through an API. Updates made in PECOS can automatically populate the corresponding NPPES record, helping ensure provider information remains accurate and consistent across both systems. [\[3\]](#references)
Records can be deactivated as well as created. NPPES carries a deactivation reason code for each deactivated record — death, disbandment, fraud, or other — together with a deactivation date, and these records are retained (and, since 2018, included in the full monthly file rather than dropped). [\[4\]](#references) A deactivated NPI is never reissued to another provider and may be reactivated if the original provider returns to practice. CMS does not independently verify most of the self-reported content of a record, which is the methodological reason the data are comprehensive in coverage but variable in currency and accuracy. The publicly available dataset is the FOIA-disclosable subset of these records, extracted and released on the cycles described in Data Access and Dissemination.
## Data Access
CMS releases only the subset of each NPPES record that is disclosable under the Freedom of Information Act; identifying elements such as Social Security Number, ITIN, and date of birth are withheld. Public dissemination of this FOIA-disclosable data began in September 2007 and is offered through three channels:[\[6\]](#references)
1. NPI Registry — a free, real-time web lookup for individual provider records, suited to verifying or retrieving a single NPI.[\[7\]](#references)
2. NPI Registry API — a public programming interface (npiregistry.cms.hhs.gov) that returns individual records as JSON in response to per-record queries. It is built for record-level lookups and does not provide bulk export.[\[7\]](#references)
3. Downloadable files — the route for working with the dataset in bulk. CMS publishes a full replacement monthly NPI file, weekly incremental files (covering NPIs newly assigned, updated, or deactivated during that week), and a monthly deactivation file in Excel format for users who need only deactivated NPIs and their deactivation dates.[\[6\]](#references)
The downloadable package is a single ZIP containing a Read Me, the Code Values reference, a Header (file-layout) document, and the FOIA-disclosable data file itself — a comma-separated file carrying both the header row and the data.[\[6\]](#references) Since June 18, 2018, the package has also bundled three reference files that externalize repeating attributes so the main file stays manageable: an Other Name reference file (additional names for Type 2 organizations), a Practice Location reference file (non-primary practice locations for Types 1 and 2), and an Endpoint reference file (health information exchange endpoints for Types 1 and 2). Each links back to the core record by NPI.[\[6\]](#references)
The weekly file is supplemental and must be used alongside the most recent monthly full-replacement file, which should be re-downloaded each month to stay current. CMS does not retain historical copies of the downloadable file — each release reflects the present state of NPPES — and the full data file contains several million records (individual and organizational, active and deactivated), making it too large to open directly in standard spreadsheet software.[\[6,8\]](#references)
## References
1. Centers for Medicare & Medicaid Services (US). [NPI fact sheet: guidance on subpart determination for Medicare organization providers who are covered entities under HIPAA](https://www.cms.gov/Regulations-and-Guidance/Administrative-Simplification/NationalProvIdentStand/Downloads/npi_fs_subparts_032106.pdf) \[Internet]. Baltimore (MD): CMS; 2006 Mar \[cited 2026 Jun 12].
2. Centers for Medicare & Medicaid Services (US). [NPIs — National Provider Identifiers](https://www.cms.gov/priorities/key-initiatives/burden-reduction/administrative-simplification/unique-identifiers/npis) \[Internet]. Baltimore (MD): CMS; \[cited 2026 Jun 12].
3. Centers for Medicare & Medicaid Services (US). [National Plan and Provider Enumeration System — privacy impact assessment (PIA)](https://security.cms.gov/pia/national-plan-and-provider-enumeration-system) \[Internet]. Baltimore (MD): CMS; \[cited 2026 Jun 12].
4. Centers for Medicare & Medicaid Services (US). [NPPES data dissemination — code values](https://www.cms.gov/regulations-and-guidance/administrative-simplification/nationalprovidentstand/downloads/data_dissemination_file-code_values.pdf) \[Internet]. Baltimore (MD): CMS; 2011 Jul \[cited 2026 Jun 12].
5. Department of Health and Human Services (US), Centers for Medicare & Medicaid Services. [HIPAA administrative simplification: standard unique health identifier for health care providers; final rule.](https://www.cms.gov/regulations-and-guidance/administrative-simplification/nationalprovidentstand/downloads/npifinalrule.pdf) Fed Regist. 2004 Jan 23;69(15):3434–69.
6. Centers for Medicare & Medicaid Services (US). [Data dissemination](https://www.cms.gov/medicare/regulations-guidance/administrative-simplification/data-dissemination) \[Internet]. Baltimore (MD): CMS; \[cited 2026 Jun 16].
7. Centers for Medicare & Medicaid Services (US). [NPI Registry](https://npiregistry.cms.hhs.gov/search) \[Internet]. Baltimore (MD): CMS; \[cited 2026 Jun 16].
8. Centers for Medicare & Medicaid Services (US). [NPPES NPI files ](https://download.cms.gov/nppes/NPI_Files.html)\[Internet]. Baltimore (MD): CMS; 2026 \[cited 2026 Jun 16].
## Resources
### Articles
* Bindman AB. [Using the National Provider Identifier for health care workforce evaluation.](https://pmc.ncbi.nlm.nih.gov/articles/PMC3983736/) Medicare Medicaid Res Rev. 2013;3(3):mmrr.003.03.b03. Published 2013 Jul 30. doi:10.5600/mmrr.003.03.b03. PMID: 24753977; PMCID: PMC3983736.
### Links
* [NPIs — National Provider Identifiers | CMS](https://www.cms.gov/priorities/key-initiatives/burden-reduction/administrative-simplification/unique-identifiers/npis)
* [Data Dissemination | CMS](https://www.cms.gov/medicare/regulations-guidance/administrative-simplification/data-dissemination)
* [NPI Registry API](https://npiregistry.cms.hhs.gov/api-page)
* [NPPES NPI downloadable files](https://download.cms.gov/nppes/NPI_Files.html)
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