Katherine Hsiao, MD
Katherine Hsiao, MD is a Gynecology Physician in San Francisco, CA, registered under NPI 1437237674. 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 1100 VAN NESS AVE FL 4, San Francisco, CA 94109. 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 |
|---|---|---|
| A51088 | CA | Gynecology Physician primary |
This provider holds licence A51088 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 - Obstetrics/gynecology
- PAC ID
- 2769644632
Medicare enrolment is recorded as approved under the provider type Practitioner - Obstetrics/gynecology. 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 Gynecology covers
A physician who specializes in diagnosis, treatment, and management of patients with gynecologic conditions. NUCC Health Care Provider Taxonomy, code 207VG0400X
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 | 1437237674 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Nov 2, 2006 |
| Last updated | Mar 3, 2026 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD |
| Practice address |
1100 VAN NESS AVE FL 4 San Francisco, CA 94109 (415) 750-7050 Fax (715) 369-1389 |
| Mailing address |
325 DISTEL CIR Los Altos, CA 94022 |
| Other identifiers |
A51088
· MEDICAL BOARD OF CALIFORNIA (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 | 4 | 3 | 7 | 2 | 3 | 7 | 6 | 7 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 6 | 7 | 4 | 3 | 5 | 6 | 5 |
Sum = 66 · next multiple of 10 = 70 · check digit = 4 · actual last digit = 4
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.