Physiological Laboratory
1,883 active US providers register Physiological Laboratory as their primary taxonomy. That is 0.02% of every provider in the registry, and the 299th largest of 584 specialties with a page here.
- Taxonomy code
- 293D00000X
- Grouping
- Laboratories
- Classification
- Physiological Laboratory
- Active providers
- 1,883
- States covered
- 50 of 51
What the code means
A laboratory that operates independently of a hospital and physician's office to furnish physiological diagnostic services (e.g. EEG's , EKG's, scans, etc.). Facilities offering ONLY physiological services are not certified as independent laboratories. If an independent laboratory offers physiological services IN ADDITION to clinical laboratory services, they are surveyed only for compliance with the clinical laboratory regulations because there are no health and safety regulations for physiological services.
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 |
|---|---|---|
| Texas | 384 | |
| California | 268 | |
| Florida | 150 | |
| New York | 80 | |
| New Jersey | 60 | |
| Illinois | 53 | |
| Colorado | 47 | |
| Ohio | 46 | |
| Georgia | 43 | |
| Arizona | 41 | |
| North Carolina | 41 | |
| Tennessee | 37 | |
| Oklahoma | 36 | |
| Louisiana | 36 | |
| Pennsylvania | 35 |
Showing the 15 largest of 50 states with at least one.
Who registers under this code
23 of these are people and 1,860 are organisations, so 99% of the code is businesses rather than clinicians. Half of them had registered by 2010, and 270 registered in the last five years, 14% of the current population.
That is close to the pace of the registry as a whole.
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, TX56
- LOS ANGELES, CA41
- DALLAS, TX36
- SAN ANTONIO, TX20
- FORT WORTH, TX19
- BROOKLYN, NY18
- PLANO, TX15
- MIAMI, FL15
- LAS VEGAS, NV15
- DENVER, CO13
What else they list
Providers whose primary code is Physiological Laboratory 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 |
|---|---|---|
| Radiology Clinic/Center | 76 | 4.0% |
| Sleep Disorder Diagnostic Clinic/Center | 75 | 4.0% |
| Diagnostic Radiology Physician | 54 | 2.9% |
| Portable X-ray and/or Other Portable Diagnostic Imaging Supplier | 53 | 2.8% |
| EEG Specialist/Technologist | 49 | 2.6% |
| Electroneurodiagnostic Specialist/Technologist | 32 | 1.7% |
| EEG Technician | 31 | 1.6% |
| Mobile Radiology Clinic/Center | 26 | 1.4% |
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.