William Ryan, M.D.
William Ryan, M.D. is a Plastic Surgery within the Head & Neck (Otolaryngology) Physician in San Francisco, CA, registered under NPI 1184811549.
Getting there
The practice address on file is 2340 CLAY ST FL 5, San Francisco, CA 94115. 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 |
|---|---|---|
| A97821 | CA | Plastic Surgery within the Head & Neck… primary |
This provider holds licence A97821 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 - Otolaryngology
- PAC ID
- 3779612213
Medicare enrolment is recorded as approved under the provider type Practitioner - Otolaryngology. 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 Plastic Surgery within the Head & Neck covers
An otolaryngologist with additional training in plastic and reconstructive procedures within the head, face, neck and associated structures, including cutaneous head and neck oncology and reconstruction, management of maxillofacial trauma, soft tissue repair and neural surgery. The field is diverse and involves a wide age range of patients, from the newborn to the aged. While both cosmetic and reconstructive surgeries are practiced, there are many additional procedures which interface with them. NUCC Health Care Provider Taxonomy, code 207YX0007X
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 | 1184811549 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Oct 1, 2007 |
| Last updated | Jan 13, 2026 |
| Status | Active |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
2340 CLAY ST FL 5 San Francisco, CA 94115 (415) 600-3073 |
| Mailing address |
PO BOX 276950 Sacramento, CA 95827 |
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 | 1 | 8 | 4 | 8 | 1 | 1 | 5 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 7 | 4 | 7 | 1 | 2 | 5 | 8 |
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.