Ellen Stein, OT
Ellen Stein, OT is an Occupational Therapist in Castro Valley, CA, registered under NPI 1821577966.
Getting there
The practice address on file is 21966 DOLORES ST, Castro Valley, CA 94546. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| OT164 | CA | Occupational Therapist primary |
This provider holds licence OT164 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
What Occupational Therapist covers
An occupational therapist is a person who has graduated from an entry-level occupational therapy program accredited by the Accreditation Council for Occupational Therapy Education (ACOTE) or predecessor organizations, or approved by the World Federation of Occupational Therapists (WFOT), or an equivalent international occupational therapy education program; has successfully completed a period of supervised fieldwork experience required by the occupational therapy program; has passed a nationally recognized entry-level examination for occupational therapists, and fulfills state requirements for licensure, certification, or registration. An occupational therapist provides interventions based on evaluation and 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 therapists 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. NUCC Health Care Provider Taxonomy, code 225X00000X
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1821577966 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Aug 9, 2018 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | OT |
| Practice address |
21966 DOLORES ST Castro Valley, CA 94546 (510) 733-2413 Fax (510) 583-1263 |
| Mailing address |
10 APPLEGATE WAY Alameda, CA 94502 |
| Other identifiers |
1043489016
· Medicaid (CA) |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 8 | 2 | 1 | 5 | 7 | 7 | 9 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 4 | 1 | 1 | 7 | 5 | 9 | 3 |
Sum = 64 · next multiple of 10 = 70 · check digit = 6 · actual last digit = 6
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.