Hematology & Oncology Physician: how many are there, and how many are in private practice?

National totals

What this specialty covers

An internist doctor of osteopathy that specializes in the treatment of the combination of hematology and oncology disorders. A doctor of osteopathy that is board eligible/certified by the American Osteopathic Board of Internal Medicine WAS able to obtain a Certificate of Special Qualifications in the field of Hematology and Oncology. The Certificate is NO longer offered.

Reading the sole-proprietor share

For this specialty, 1,605 active NPI records, or 11.4%, are flagged as sole proprietors in NPPES. Because that flag is self-reported, it is an imperfect proxy for private practice: it may not capture every privately practicing physician and does not by itself describe ownership, employment, or practice structure.

By state

New NPI registrations by year

Counts reflect the year each NPI was first issued, among records still active today. The final year is partial: this data covers through 2026-01-11.

Data notes

• The sole-proprietor field is self-reported by the provider in NPPES and is an imperfect proxy for private practice.
• A sole-proprietor count shown as <11 is suppressed: the true value is below 11, which could include zero.
• These are active NPI records with this taxonomy as primary, not a direct census of practicing physicians, full-time equivalents, or patient volume.
• An NPI enumeration year shows when the NPI was first recorded, not when the clinician entered this specialty or began practicing.
• Providers are counted once, by their primary taxonomy code only.

Source: CMS National Plan and Provider Enumeration System (NPPES) Data Dissemination file, FOIA-disclosable public data under CMS-6060-N. Aggregated by Hero EMR on 2026-08-03; deactivated NPIs excluded; specialty assigned from the primary taxonomy code (NUCC 25.1). Counts below 11 are suppressed. Individual providers are never published. All provider data pages.

Common questions