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

National totals

What this specialty covers

An internist who specializes in the diagnosis and treatment of all types of cancer and other benign and malignant tumors. This specialist decides on and administers therapy for these malignancies as well as consults with surgeons and radiotherapists on other treatments for cancer.

Reading the sole-proprietor share

For Medical Oncology Physician records, the sole-proprietor share indicates how many active primary-taxonomy records are flagged in NPPES as sole proprietors: 518 records, or 12.0%. This self-reported field can help describe organization status, but it is an imperfect proxy for private practice because it may not consistently capture ownership, employment, group structure, or affiliation.

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.
• An NPI is an administrative identifier, so active records may not equal unique practicing physicians.
• Primary taxonomy is a classification choice and may differ from a provider's other specialties or current practice.
• 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