Allopathic & Osteopathic Physicians / 204R00000X
Individual · classification
204R00000X Electrodiagnostic Medicine Physician
204R00000X is the taxonomy code for Electrodiagnostic Medicine, in the NUCC group “Allopathic & Osteopathic Physicians”. It is a code for individual providers — the kind used on a Type 1 NPI. It has no entry in the CMS Medicare taxonomy crosswalk.
- 1Taxonomy code 204R00000X
- 2Level Classification
- 3Medicare specialty Not in the crosswalk
- 4Codes in this group 238
Definition
Electrodiagnostic medicine is the medical subspecialty that applies neurophysiologic techniques to diagnose, evaluate, and treat patients with impairments of the neurologic, neuromuscular, and/or muscular systems. Qualified physicians are trained in performing electrophysiological testing and interpretation of the test data. They require knowledge in anatomy, physiology, kinesiology, histology, and pathology of the brain, spinal cord, autonomic nerves, cranial nerves, peripheral nerves, neuromuscular junction, and muscles. They must know clinical features and treatment of diseases of the central, peripheral, and autonomic nervous systems, as well as those of neuromuscular junction and muscle. Physicians also require special knowledge about electric signal processing, including waveform analysis, electronics and instrumentation, stimulation and recording equipment, and statistics.
— NUCC Health Care Provider Taxonomy, version 26.1
Where 204R00000X sits
- Group: Allopathic & Osteopathic Physicians — code 19 of 238 in the group
- Classification: Electrodiagnostic Medicine 204R00000X
Electrodiagnostic Medicine has no specializations, so 204R00000X is the only code for it. A provider may report more than one taxonomy code on an NPI but marks one as primary.
Medicare
204R00000X has no entry in the CMS Medicare Provider and Supplier Taxonomy Crosswalk. That usually means Medicare does not enroll this kind of provider under its own specialty — the provider can still hold an NPI and use this code on claims to other payers.
Related codes
No other codes share the classification Electrodiagnostic Medicine. The rest of Allopathic & Osteopathic Physicians is on the group page.
History of 204R00000X
204R00000X was added to the code set in 2011.
- 2011-01-01 — new
Similar codes in other groups
If 204R00000X 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)
Find providers with 204R00000X
Using 204R00000X
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). Checked 2026-10-24. Methodology.