Health Service Psychologist
1,138 active US providers register Health Service Psychologist as their primary taxonomy. That is 0.01% of every provider in the registry, and the 373rd largest of 584 specialties with a page here.
- Taxonomy code
- 103TH0100X
- Grouping
- Behavioral Health & Social Service Providers
- Classification
- Psychologist
- Specialization
- Health Service
- Active providers
- 1,138
- States covered
- 48 of 51
What the code means
A psychologist, certified/licensed at the independent practice level in his/her state, who is duly trained and experienced in the delivery of direct, preventative, assessment, and therapeutic intervention services to individuals whose growth, adjustment, or functioning is actually impaired or is demonstrably at high risk of impairment (1974).
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 |
|---|---|---|
| Massachusetts | 97 | |
| California | 84 | |
| Indiana | 78 | |
| North Carolina | 70 | |
| Texas | 68 | |
| Oklahoma | 57 | |
| Tennessee | 56 | |
| Florida | 55 | |
| Ohio | 50 | |
| Michigan | 47 | |
| New York | 34 | |
| Missouri | 30 | |
| Illinois | 28 | |
| Maryland | 23 | |
| Minnesota | 21 |
Showing the 15 largest of 48 states with at least one.
Who registers under this code
950 of these are people and 188 are organisations, so 17% of the code is businesses rather than clinicians. Half of them had registered by 2015, and 341 registered in the last five years, 30% 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.
- INDIANAPOLIS, IN27
- OKLAHOMA CITY, OK17
- BOSTON, MA17
- WASHINGTON, DC14
- HOUSTON, TX13
- BALTIMORE, MD13
- SAINT LOUIS, MO12
- CHICAGO, IL12
- LAS VEGAS, NV11
- TULSA, OK10
What else they list
Providers whose primary code is Health Service Psychologist 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 |
|---|---|---|
| Clinical Psychologist | 144 | 12.7% |
| Psychologist | 101 | 8.9% |
| Clinical Child & Adolescent Psychologist | 38 | 3.3% |
| Counseling Psychologist | 31 | 2.7% |
| Cognitive & Behavioral Psychologist | 29 | 2.5% |
| Mental Health Counselor | 26 | 2.3% |
| Clinical Neuropsychologist | 24 | 2.1% |
| School Psychologist | 22 | 1.9% |
Nearby specialties
Other taxonomies NUCC files under Psychologist.
- Intellectual & Developmental Disabilities Psychologist1,234
- Forensic Psychologist913
- Group Psychotherapy Psychologist807
- Rehabilitation Psychologist795
- Addiction (Substance Use Disorder) Psychologist740
- Prescribing (Medical) Psychologist583
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.