Occupational Therapy Assistant
41,485 active US providers register Occupational Therapy Assistant as their primary taxonomy. That is 0.4% of every provider in the registry, and the 52nd largest of 584 specialties with a page here.
- Taxonomy code
- 224Z00000X
- Grouping
- Respiratory, Developmental, Rehabilitative and Restorative Service Providers
- Classification
- Occupational Therapy Assistant
- Active providers
- 41,485
- States covered
- 51 of 51
What the code means
An occupational therapy assistant is a person who has graduated from an occupational therapy assistant program accredited by the Accreditation Council for Occupational Therapy Education (ACOTE) or predecessor organizations, has successfully completed a period of supervised fieldwork experience required by the accredited occupational therapy assistant program, has passed a nationally recognized entry-level examination for occupational therapy assistants, and fulfills state requirements for licensure, certification, or registration. An occupational therapy assistant provides interventions under the supervision of an occupational therapist which emphasize the therapeutic use of everyday life activities (i.e., occupations) with individuals or groups for the purpose of facilitating participation in roles and situations and in home, school, workplace, community and other settings. Occupational therapy services are provided for the purpose of promoting health and wellness and are provided to those who have or are at risk for developing an illness, injury, disease, disorder, condition, impairment, disability, activity limitation, or participation restriction. Occupational therapy assistants address the physical, cognitive, psychosocial, sensory, and other aspects of occupational performance in a variety of contexts to support engagement in everyday life activities that affect health, well-being, and quality of life.
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 | 4,271 | |
| Florida | 3,847 | |
| New York | 2,740 | |
| Ohio | 2,414 | |
| Pennsylvania | 2,150 | |
| California | 1,868 | |
| Illinois | 1,500 | |
| Wisconsin | 1,464 | |
| North Carolina | 1,357 | |
| Virginia | 1,091 | |
| Indiana | 1,090 | |
| Arkansas | 1,062 | |
| Arizona | 1,058 | |
| Missouri | 1,058 | |
| Tennessee | 1,008 |
Showing the 15 largest of 51 states with at least one.
Who registers under this code
Almost all of these are individual clinicians: 41,295 people against 190 organisations. Half of them had registered by 2017, and 12,496 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.
- NORTH CANTON, OH427
- HOUSTON, TX386
- SAN ANTONIO, TX346
- LOUISVILLE, KY328
- PHOENIX, AZ287
- ORLANDO, FL259
- MIAMI, FL215
- BROOKLYN, NY207
- OKLAHOMA CITY, OK166
- DALLAS, TX159
What else they list
Providers whose primary code is Occupational Therapy Assistant 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 |
|---|---|---|
| Occupational Therapist | 132 | 0.3% |
| Behavior Technician | 108 | 0.3% |
| Massage Therapist | 56 | 0.1% |
| Physical Therapy Assistant | 52 | 0.1% |
| Speech-Language Pathologist | 49 | 0.1% |
| Physical Therapist | 48 | 0.1% |
| Environmental Modification Occupational Therapy Assistant | 41 | 0.1% |
| Pediatric Occupational Therapist | 35 | 0.1% |
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.