Alexander Clarke, M.D.
Alexander Clarke, M.D. is a Psychiatry Physician in Redwood City, CA, registered under NPI 1982091062. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 611 VETERANS BLVD # 116, Redwood City, CA 94063. 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 |
|---|---|---|
| 143985 | CA | Psychiatry Physician primary |
This provider holds licence 143985 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 Psychiatry covers
A Psychiatrist specializes in the prevention, diagnosis, and treatment of mental disorders, emotional disorders, psychotic disorders, mood disorders, anxiety disorders, substance-related disorders, sexual and gender identity disorders and adjustment disorders. Biologic, psychological, and social components of illnesses are explored and understood in treatment of the whole person. Tools used may include diagnostic laboratory tests, prescribed medications, evaluation and treatment of psychological and interpersonal problems with individuals and families, and intervention for coping with stress, crises, and other problems. NUCC Health Care Provider Taxonomy, code 2084P0800X
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 | 1982091062 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 16, 2015 |
| Last updated | Nov 17, 2020 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
611 VETERANS BLVD # 116 Redwood City, CA 94063 (650) 382-2090 |
| Mailing address |
548 MARKET ST STE 74687 San Francisco, CA 94104 |
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 | 9 | 8 | 2 | 0 | 9 | 1 | 0 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 9 | 7 | 2 | 0 | 9 | 2 | 0 | 3 |
Sum = 58 · next multiple of 10 = 60 · check digit = 2 · actual last digit = 2
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.