providerfile
Taxonomy 207RH0003X
INTERNAL MEDICINE17,524 ON THE REGISTER87

Hematology & Oncology Physician

17,524 active US providers register Hematology & Oncology Physician as their primary taxonomy. That is 0.2% of every provider in the registry, and the 87th largest of 584 specialties with a page here.

Taxonomy code
207RH0003X
Grouping
Allopathic & Osteopathic Physicians
Classification
Internal Medicine
Specialization
Hematology & Oncology
Active providers
17,524
States covered
51 of 51

What the code means

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.

Definition quoted verbatim from the NUCC Health Care Provider Taxonomy code set, version 25.1. Not paraphrased.

Where they are

Counted by practice location, not by mailing address or by licence state. A provider practising across a state line is counted where they practise.

Showing the 15 largest of 51 states with at least one.

Who registers under this code

14,072 of these are people and 3,452 are organisations, so 20% of the code is businesses rather than clinicians. Half of them had registered by 2007, and 914 registered in the last five years, 5% of the current population.

That is a slow-growing code, which usually means an established field replacing retirements rather than expanding.

Where the practices are

By practice-location city. City counts are noisier than state counts, because a large employer files one address for many providers.

What else they list

Providers whose primary code is Hematology & Oncology Physician most often carry these secondary taxonomies as well. This is the closest thing the registry has to a map of which specialties overlap in practice, and it is not published anywhere else.

Nearby specialties

Other taxonomies NUCC files under Internal Medicine.

Looking up a specific provider

These counts come from the monthly NPPES file. To check one provider, use their NPI: the lookup reads the live registry and shows whether the identifier is still active, which the monthly file cannot tell you about the last few weeks.

Counts from npidata_pfile_20050523-20260712.csv, built 2026-08-09. Primary taxonomy only, deactivated identifiers excluded.