Carl Grunfeld, M.D.
Carl Grunfeld, M.D. is an Endocrinology, Diabetes & Metabolism Physician in San Francisco, CA, registered under NPI 1659487635.
Getting there
The practice address on file is 4150 CLEMENT ST METABOLISM SECTION 111F, San Francisco, CA 94121. 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 |
|---|---|---|
| G41853 | CA | Endocrinology, Diabetes & Metabolism… primary |
This provider holds licence G41853 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 Endocrinology, Diabetes & Metabolism covers
An internist who concentrates on disorders of the internal (endocrine) glands such as the thyroid and adrenal glands. This specialist also deals with disorders such as diabetes, metabolic and nutritional disorders, obesity, pituitary diseases and menstrual and sexual problems. NUCC Health Care Provider Taxonomy, code 207RE0101X
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 | 1659487635 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Aug 22, 2006 |
| Last updated | Jul 12, 2007 |
| Status | Active |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
4150 CLEMENT ST METABOLISM SECTION 111F San Francisco, CA 94121 (415) 750-2005 Fax (415) 750-6927 |
| Mailing address |
VETERANS AFFAIRS MEDICAL CENTER 4150 CLEMENT STREET San Francisco, CA 94121 |
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 | 6 | 5 | 9 | 4 | 8 | 7 | 6 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 1 | 9 | 8 | 8 | 5 | 6 | 6 |
Sum = 75 · next multiple of 10 = 80 · check digit = 5 · actual last digit = 5
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.