> For the complete documentation index, see [llms.txt](https://wiki.medicaiddatalearningnetwork.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://wiki.medicaiddatalearningnetwork.org/basics/identifying-provider-specialty.md). # Identifying Provider Specialty Provider specialty is often needed when analyzing service use, access, spending, or provider participation in Medicaid. However, specialty information in TAF can be incomplete or inconsistent across data sources. One practical approach is to assign specialty using a hierarchy of sources, beginning with the source likely to be most reliable and then filling in missing values from other available files. ## Suggested hierarchy A commonly used approach is to identify provider specialty using the following sequence: ## 1. Medicare Data on Provider Practice and Specialty First, assign provider specialty using the Medicare Data on Provider Practice and Specialty, or MD-PPAS, file. MD-PPAS reflects provider specialty information from the Medicare Provider Enrollment, Chain, and Ownership System, or PECOS. Because PECOS is used for Medicare billing, providers have incentives to keep their enrollment information updated. This makes MD-PPAS a useful source of provider specialty for clinicians who participate in Medicare. However, MD-PPAS will generally only be useful for providers enrolled in Medicare. It may be less complete for analyses focused on providers who rarely participate in Medicare, such as pediatric providers or providers serving primarily Medicaid-only populations. ## 2. TAF taxonomy code from Other Services claims If specialty is missing from MD-PPAS, the next step is to use provider taxonomy codes from the TAF. One approach is to identify the taxonomy code most commonly observed for the provider across Other Services claims. In practice, this means assigning the provider the taxonomy code that appears on the plurality of that provider’s OT claims. This can help identify the provider’s most common reported specialty in Medicaid claims and encounters. ## 3. TAF Annual Provider file If specialty is still missing, another option is to use specialty information from the TAF Annual Provider, or APR, file. The APR file may contain additional provider-level information that can be useful when specialty is not available from MD-PPAS or claim-level taxonomy codes. Users should assess the completeness and consistency of APR specialty fields for the states and years included in their analysis. ## 4. NPPES primary specialty Finally, if specialty cannot be identified using the sources above, the provider’s primary specialty can be assigned using the National Plan and Provider Enumeration System, or NPPES, file. NPPES is useful because it contains national provider information linked to NPIs. However, users should be aware that NPPES specialty information may not always reflect how a provider is practicing in Medicaid during a specific study period. ## Practical considerations This hierarchy is intended to prioritize sources that may be more reliable for identifying practicing specialty, while preserving the ability to fill in missing values when the preferred source is unavailable. The best approach may differ depending on the study population, provider types, service categories, and states included in the analysis. For studies focused on pediatric populations, behavioral health, long-term services and supports, or providers with limited Medicare participation, users should be especially cautious about relying on MD-PPAS alone. In those cases, TAF taxonomy codes, APR information, and NPPES may play a larger role. Researchers should document the specialty assignment hierarchy used in their analysis, report how often each source contributed to the final specialty assignment, and consider sensitivity analyses when provider specialty is central to the study findings. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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