Taxonomy versus claims-based specialties

When healthcare providers register for a National Provider Identifier (NPI) number, they select a taxonomy that reflects their specialization and education. This data point, however, may become outdated as a provider finishes training or branches into a sub-specialty focus.

To more accurately reflect a provider’s practice patterns, we assign them a claims-based specialty in our PhysicianView product.

In the list below, we spotlight differences in taxonomy-based specialties and claims-based specialties to see areas where our healthcare commercial intelligence better classifies the providers in our PhysicianView product.

Difference between NPI taxonomy and claims-based specialty by number of providers

Taxonomy codeNPI taxonomy descriptionClaims-based specialtyNumber of providers
207R00000XInternal MedicineCardiology3,733
207R00000XInternal MedicineGastroenterology2,605
207R00000XInternal MedicinePulmonology2,310
207R00000XInternal MedicineNephrology1,965
207RC0200XCritical Care MedicinePulmonology1,793
207R00000XInternal MedicineOncology1,662
207Q00000XFamily MedicineEmergency Medicine1,505
207Q00000XFamily MedicineEmergency Medicine1,485
207R00000XInternal MedicineInfectious Disease1,463
207XX0005XSports MedicineOrthopedic Surgery1,368
207R00000XInternal MedicineEndocrinology1,353
207R00000XInternal MedicineRheumatology1,031
207R00000XInternal MedicineDiagnostic Radiology934
208600000XSurgeryVascular Surgery877
207R00000XInternal MedicineCardiology795

Fig 1. Data from the Definitive Healthcare PhysicianView product. Data examines where the taxonomy-based primary specialty is different from the claims-based specialty. Claims-based specialty is a proprietary designation from Definitive Healthcare. Data is sourced from proprietary research, the NPI registry and Physician Compare. Data accurate as of July 2022.


Claims-based specialty better categorizes nearly 18,000 internal medicine doctors

Ten of the 15 pairs of NPI-based and claims-based specialties provide more granular therapy area information for 17,850 providers identified with an internal medicine taxonomy code. These physicians are more accurately described as cardiology, gastroenterology, pulmonology and nephrology specialists when their diagnosis and procedure activity are taken into account.

Why are claims-based medical specialties important?

Compared to self-reported taxonomies, claims-based specialties in PhysicianView use healthcare commercial intelligence to better represent the type of clinical activity a provider performs. It allows for categorization of physicians based on their expertise and provides an up-to-date view of the procedures they’re performing.

For example, if an endocrinology professional association wants to target all endocrinologist providers, they would miss more than 1,300 potential contacts that have an internal medicine taxonomy but bill predominantly for endocrinology codes.

Or, if a biopharma company wants to know more about doctors who treat cancer patients, they could miss more than 1,500 providers with an oncology claims-based specialty who have a different taxonomy-based specialty.

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