Robert Williams, M.D
NPI 1225193667 · Internal Medicine Physician · San Francisco, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Robert Williams, M.D is a Internal Medicine Physician provider in San Francisco, CA (NPI 1225193667).
Provider details
- NPI number
- 1225193667
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D
- Sex
- Male
- Sole proprietor
- Yes
- License
- A92069 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
201 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Hemoglobin A1c Level83036 | 167 | $10 |
| Automated Urinalysis Test81003 | 22 | $2 |
| Detection Test By Immunoassay With Direct Visual Observation for Severe Acute Respiratory Syndrome Coronavirus 2 (covid-19)87811 | 12 | $41 |
Typical Medicare-allowed amounts for these services range $2–$41 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 75 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 277 | 80 |
| Amlodipine Besylate | 233 | 67 |
| Metformin Hcl | 181 | 49 |
| Lisinopril | 150 | 32 |
| Losartan Potassium | 146 | 41 |
| Pravastatin Sodium | 113 | 31 |
| Gabapentin | 112 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-12-26
- Last updated
- 2007-07-08
Frequently asked questions
- What is Robert Williams's NPI number?
- Robert Williams's National Provider Identifier (NPI) is 1225193667, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Robert Williams's specialty?
- Robert Williams is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Robert Williams located?
- Robert Williams's practice location on file with NPPES is 240 Shotwell St, San Francisco, CA 94110-1323.
- What is Robert Williams's phone number?
- The practice phone number listed in the NPPES registry for Robert Williams is (415) 552-1013.
- Does Robert Williams accept Medicare?
- Robert Williams is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Robert Williams's NPI active?
- Yes — Robert Williams's NPI (1225193667) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.