Hematology/Oncology: Medicare enrollment by state

Taxonomy codes for hematology/oncology

CMS's crosswalk maps 1 NUCC taxonomy code to Medicare specialty 83. A provider enrolling as hematology/oncology should hold one of them as the primary taxonomy on their NPI.

Where it is concentrated

Raw counts follow population, so the more telling figure is each state's share: what fraction of the state's Medicare-enrolled NPIs are hematology/oncology. Nationally the specialty is 0.5% of enrolled NPIs. The highest shares are in Hawaii (0.7%), Massachusetts (0.6%), Washington (0.6%); the lowest in Idaho (0.2%), Alaska (0.3%), Wyoming (0.3%). 51 of the 51 (50 states and DC) have at least one enrolled.

Billing versus order-and-refer enrollment

Medicare enrolls practitioners in two ways. A full enrollment lets the provider bill Medicare for their own services; it is what the 12,233 above count. An order-and-refer-only enrollment lets a provider who never bills Medicare — a resident, a VA or military physician, a dentist ordering imaging — still order tests, equipment and referrals that Medicare pays for. 481 hematology/oncology NPIs hold that limited enrollment.

Every state

Counts are unique NPIs enrolled in each state; a provider enrolled in two states counts in both. The share is of all Medicare-enrolled NPIs in that state.

Sources: CMS Medicare Fee-For-Service Public Provider Enrollment, extract of 2026-09-29; CMS Medicare Provider and Supplier Taxonomy Crosswalk, August 2026. Checked 2026-10-24. Methodology.