Ronald Clark, M.D.
Ronald Clark, M.D. is a Surgery Physician in San Francisco, CA, registered under NPI 1477631919. 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 909 HYDE ST SUITE 325, 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 |
|---|---|---|
| C357640 | CA | Surgery Physician primary |
This provider holds licence C357640 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 Surgery covers
A general surgeon has expertise related to the diagnosis - preoperative, operative and postoperative management - and management of complications of surgical conditions in the following areas: alimentary tract; abdomen; breast, skin and soft tissue; endocrine system; head and neck surgery; pediatric surgery; surgical critical care; surgical oncology; trauma and burns; and vascular surgery. General surgeons increasingly provide care through the use of minimally invasive and endoscopic techniques. Many general surgeons also possess expertise in transplantation surgery, plastic surgery and cardiothoracic surgery. NUCC Health Care Provider Taxonomy, code 208600000X
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 | 1477631919 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Nov 1, 2006 |
| Last updated | Dec 17, 2010 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
909 HYDE ST SUITE 325 San Francisco, CA 94109 (415) 775-2795 Fax (415) 775-3025 |
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 | 7 | 7 | 6 | 3 | 1 | 9 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 5 | 7 | 3 | 3 | 2 | 9 | 2 |
Sum = 61 · next multiple of 10 = 70 · check digit = 9 · actual last digit = 9
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.