William Chen, MD
NPI 1417452251 · Radiation Oncology Physician · San Francisco, CA
Enrolled with Medicare as Practitioner - Radiation Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Chen, MD is a Radiation Oncology Physician provider in San Francisco, CA (NPI 1417452251).
Provider details
- NPI number
- 1417452251
- Entity type
- Individual
- Primary specialty
- Radiation Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
8 yrs in NPPES registry
- Profile completeness28% of score
83% of core fields populated
- Practice footprint17% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
1,124 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) |
|---|---|---|
| Ct Guidance for Insertion of Radiation Therapy Fields77014 | 387 | $51 |
| Calculation of Radiation Therapy Dose77300 | 152 | $37 |
| Radiation Treatment Management, 5 Treatment Sessions77427 | 118 | $219 |
| Design and Construction of Complex Radiation Treatment Device77334 | 104 | $69 |
| New Patient Office Or Other Outpatient Visit With a High Level of Medical Decision Making, If Using Time, 60 Minutes Or More99205 | 54 | $202 |
| Management of Cranial Lesion Surgery Using Radiation Over Multiple Sessions77435 | 53 | $729 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 1 distinct drug on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Ondansetron Hcl | 13 | 13 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Additional practice locations (1)
- 2425 Geary BlvdSan Francisco, CA 94115-3358Phone: (415) 833-2000
Registry dates
- Enumerated
- 2018-03-26
- Last updated
- 2023-06-13
- Certified
- 2023-06-13
Frequently asked questions
- What is William Chen's NPI number?
- William Chen's National Provider Identifier (NPI) is 1417452251, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Chen's specialty?
- William Chen is listed in the NPPES registry with a primary specialty of Radiation Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is William Chen located?
- William Chen's practice location on file with NPPES is 1600 Divisadero St Ste H-1031, San Francisco, CA 94143-3010.
- What is William Chen's phone number?
- The practice phone number listed in the NPPES registry for William Chen is (415) 353-7175.
- Does William Chen accept Medicare?
- William Chen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Chen's NPI active?
- Yes — William Chen's NPI (1417452251) is active in the NPPES registry as of the last update on 2023-06-13.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.