William Silveira, MD
NPI 1447494398 · Radiation Oncology Physician · Clovis, CA
Enrolled with Medicare as Practitioner - Radiation Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Silveira, MD is a Radiation Oncology Physician provider in Clovis, CA (NPI 1447494398).
Provider details
- NPI number
- 1447494398
- Entity type
- Individual
- Primary specialty
- Radiation Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
- License
- A115447 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
17 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
3,278 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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 | 1,177 | $45 |
| Calculation of Radiation Therapy Dose77300 | 557 | $33 |
| Design and Construction of Complex Radiation Treatment Device77334 | 319 | $61 |
| Radiation Treatment Management, 5 Treatment Sessions77427 | 314 | $191 |
| Telephone Medical Discussion With Physician, 5-10 Minutes99441 | 187 | $58 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 96 | $131 |
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 |
|---|---|---|
| Dexamethasone | 20 | 11 |
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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$18 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2009-04-22
- Last updated
- 2021-03-18
- Certified
- 2021-03-18
Frequently asked questions
- What is William Silveira's NPI number?
- William Silveira's National Provider Identifier (NPI) is 1447494398, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Silveira's specialty?
- William Silveira is listed in the NPPES registry with a primary specialty of Radiation Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is William Silveira located?
- William Silveira's practice location on file with NPPES is 785 N. Medical Center Drive West, Clovis, CA 93611.
- What is William Silveira's phone number?
- The practice phone number listed in the NPPES registry for William Silveira is (559) 387-1600.
- Does William Silveira accept Medicare?
- William Silveira is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Silveira's NPI active?
- Yes — William Silveira's NPI (1447494398) is active in the NPPES registry as of the last update on 2021-03-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.