Taxonomy 207RA0201X

Allergy & Immunology (Internal Medicine) Physician

742 active US providers register Allergy & Immunology (Internal Medicine) Physician as their primary taxonomy. That is 0.01% of every provider in the registry, and the 422nd largest of 584 specialties with a page here.

Taxonomy code: 207RA0201X
Grouping: Allopathic & Osteopathic Physicians
Classification: Internal Medicine
Specialization: Allergy & Immunology
Active providers: 742
States covered: 47 of 51

What the code means

An internist doctor of osteopathy that specializes in the treatment of allergy and immunologic disorders. A doctor of osteopathy that is board eligible/certified by the American Osteopathic Board of Internal Medicine can obtain a Certificate of Special Qualifications in the field of Allergy & Immunology.

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.

State	Providers	Share
California	104
New York	75
Texas	63
Illinois	35
Maryland	34
Florida	34
Pennsylvania	30
Missouri	30
Massachusetts	27
Wisconsin	23
Michigan	22
Colorado	21
New Jersey	19
Virginia	18
Georgia	16

Showing the 15 largest of 47 states with at least one.

Who registers under this code

593 of these are people and 149 are organisations, so 20% of the code is businesses rather than clinicians. Half of them had registered by 2008, and 45 registered in the last five years, 6% 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.

HOUSTON, TX23
NEW YORK, NY20
SAINT LOUIS, MO20
BOSTON, MA16
BALTIMORE, MD15
CHICAGO, IL13
SAN FRANCISCO, CA13
LOS ANGELES, CA10
BETHESDA, MD10
SEATTLE, WA9

What else they list

Providers whose primary code is Allergy & Immunology (Internal Medicine) 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.

Also listed	Providers	Share
Internal Medicine Physician	163	22.0%
Allergy & Immunology Physician	80	10.8%
Student in an Organized Health Care Education/Training Program	41	5.5%
Allergy Physician	34	4.6%
Pediatric Allergy/Immunology Physician	27	3.6%
Pediatrics Physician	26	3.5%
Rheumatology Physician	23	3.1%
Pulmonary Disease Physician	16	2.2%

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.