Gillian Hsieh, MD
Gillian Hsieh, MD is an Obstetrics & Gynecology Physician in Mountain View, CA, registered under NPI 1063765576.
Getting there
The practice address on file is 2490 HOSPITAL DR STE 111, Mountain View, CA 94040. 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 |
|---|---|---|
| A134657 | CA | Obstetrics & Gynecology Physician primary |
This provider holds licence A134657 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 - Gynecological Oncology
- PAC ID
- 5991023327
Medicare enrolment is recorded as approved under the provider type Practitioner - Gynecological Oncology. 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 Obstetrics & Gynecology covers
An obstetrician/gynecologist possesses special knowledge, skills and professional capability in the medical and surgical care of the female reproductive system and associated disorders. This physician serves as a consultant to other physicians and as a primary physician for women. NUCC Health Care Provider Taxonomy, code 207V00000X
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 | 1063765576 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Oct 22, 2012 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
2490 HOSPITAL DR STE 111 Mountain View, CA 94040 (650) 934-7520 |
| Mailing address |
2350 W EL CAMINO REAL FL 2 Mountain View, CA 94040 |
| Other identifiers |
BP10039750
· TEXAS PHYSICIAN IN TRAINING (TX) |
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 | 0 | 6 | 3 | 7 | 6 | 5 | 5 | 7 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 3 | 3 | 5 | 6 | 1 | 5 | 5 |
Sum = 54 · next multiple of 10 = 60 · 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.