Allopathic & Osteopathic Physicians / 207K00000X
Individual · classification · Medicare specialty 03
207K00000X Allergy & Immunology Physician
207K00000X is the taxonomy code for Allergy & Immunology, in the NUCC group “Allopathic & Osteopathic Physicians”. It is a code for individual providers — the kind used on a Type 1 NPI. Medicare maps it to specialty 03, Physician/Allergy/ Immunology, under which 4,224 practitioners are enrolled.
- 1Taxonomy code 207K00000X
- 2Level Classification
- 3Medicare specialty 03 Physician/Allergy/ Immunology
- 4Codes in this group 238
Definition
An allergist-immunologist is trained in evaluation, physical and laboratory diagnosis, and management of disorders involving the immune system. Selected examples of such conditions include asthma, anaphylaxis, rhinitis, eczema, and adverse reactions to drugs, foods, and insect stings as well as immune deficiency diseases (both acquired and congenital), defects in host defense, and problems related to autoimmune disease, organ transplantation, or malignancies of the immune system.
— NUCC Health Care Provider Taxonomy, version 26.1
Where 207K00000X sits
- Group: Allopathic & Osteopathic Physicians — code 1 of 238 in the group
- Classification: Allergy & Immunology 207K00000X
This is the general code for Allergy & Immunology. 2 more specific codes sit beneath it; pick one of those when the provider's training or certification matches it, and this one otherwise. A provider may report more than one taxonomy code on an NPI but marks one as primary.
Medicare
CMS's taxonomy crosswalk links 207K00000X to Medicare specialty 03 (Physician/Allergy/ Immunology). That specialty — not the taxonomy code itself — is what Medicare enrollment records and uses for payment. 4,224 practitioners are enrolled under it nationally, and 2 other taxonomy codes map to the same specialty.
Other codes under the same Medicare specialty: 207KA0200X Allergy Physician; 207KI0005X Clinical & Laboratory Immunology (Allergy & Immunology) Physician.
Related codes
| Code | Allergy & Immunology — specializations |
|---|---|
| 207KA0200X | Allergy |
| 207KI0005X | Clinical & Laboratory Immunology |
History of 207K00000X
NUCC's earliest recorded change to 207K00000X is from 2007 (added definition, added source).
- 2007-07-01 — added definition, added source
Similar codes in other groups
If 207K00000X is not quite right, these codes in other groups share a word with it — often the same field practised by a different kind of provider:
- 246QI0000X Immunology Pathology Specialist/Technologist (Technologists, Technicians & Other Technical Service Providers)
Find providers with 207K00000X
Using 207K00000X
The code goes in the taxonomy field of the NPI application in NPPES, and on claims where a payer asks for it — box 24J (shaded) or 33b on the CMS-1500 with the ZZ qualifier, or the PRV segment of an 837 electronic claim. Payers match it against the taxonomy on the NPI record and, for Medicare, against the specialty on the enrollment, so all three should agree. To see which code a provider uses, search their NPI in the lookup.
Sources: NUCC Health Care Provider Taxonomy code set, version 26.1 (CSV); CMS Medicare Provider and Supplier Taxonomy Crosswalk, August 2026; CMS Medicare Fee-For-Service Public Provider Enrollment, extract of 2026-09-29. Checked 2026-10-24. Methodology.