207R00000X Internal Medicine Physician

Definition

A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.

— NUCC Health Care Provider Taxonomy, version 26.1

Where 207R00000X sits

• Group: Allopathic & Osteopathic Physicians — code 42 of 238 in the group
• Classification: Internal Medicine 207R00000X

This is the general code for Internal Medicine. 30 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 207R00000X to Medicare specialty 11 (Physician/Internal Medicine). That specialty — not the taxonomy code itself — is what Medicare enrollment records and uses for payment. 128,064 practitioners are enrolled under it nationally, and 25 other taxonomy codes map to the same specialty.

Other codes under the same Medicare specialty: 207QB0505X Diabetology (Internal Medicine) Physician; 207RA0000X Adolescent Medicine (Internal Medicine) Physician; 207RA0001X Advanced Heart Failure and Transplant Cardiology Physician; 207RA0201X Allergy & Immunology (Internal Medicine) Physician; 207RA0401X Addiction Medicine (Internal Medicine) Physician; 207RB0002X Obesity Medicine (Internal Medicine) Physician; 207RC0000X Cardiovascular Disease Physician; 207RC0200X Critical Care Medicine (Internal Medicine) Physician; and 17 more.

Related codes

History of 207R00000X

NUCC's earliest recorded change to 207R00000X is from 2007 (added definition, added source), and has been revised 1 time since.

• 2007-07-01 — added definition, added source
• 2011-07-01 — modified source

Similar codes in other groups

If 207R00000X 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:

• 125Q00000X Oral Medicine Dentistry (Dental Providers)
• 163WC0200X Critical Care Medicine Registered Nurse (Nursing Service Providers)
• 173000000X Legal Medicine (Other Service Providers)
• 1835E0208X Emergency Medicine Pharmacist (Pharmacy Service Providers)
• 364SC0200X Critical Care Medicine Clinical Nurse Specialist (Physician Assistants & Advanced Practice Nursing Providers)
• 363LC0200X Critical Care Medicine Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers)

Using 207R00000X

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.