Gemma Guillermo, M.D.
Gemma Guillermo, M.D. is a Psychiatry Physician in Redwood City, CA, registered under NPI 1831154418. 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 170 ALAMEDA DE LAS PULGAS 1EAST, SEQUOIA HOSPITAL, Redwood City, CA 94062. 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 |
|---|---|---|
| 61066 | CA | Psychiatry Physician primary |
This provider holds licence 61066 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Psychiatry
- PAC ID
- 2769445113
Medicare enrolment is recorded as approved under the provider type Practitioner - Psychiatry. This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
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 | 1831154418 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 18, 2006 |
| Last updated | Feb 13, 2019 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
170 ALAMEDA DE LAS PULGAS 1EAST, SEQUOIA HOSPITAL Redwood City, CA 94062 (650) 367-5559 Fax (650) 368-3754 |
| Mailing address |
2290 VERA AVE Redwood City, CA 94061 |
| Other identifiers |
3967836
(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 | 3 | 1 | 1 | 5 | 4 | 4 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 6 | 1 | 2 | 5 | 8 | 4 | 2 |
Sum = 62 · next multiple of 10 = 70 · check digit = 8 · actual last digit = 8
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.