Quick answers
- Does William R. Silveira accept Medicare assignment?
- Yes. Medicare's clinician data says William R. Silveira accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does William R. Silveira see?
- In 2024, CMS data shows 312 Original Medicare patients and 3,443 services for William R. Silveira. This counts Original Medicare only and measures volume, not quality.
- What is William R. Silveira's NPI number?
- 1447494398. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for William R. Silveira, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 312 |
|---|---|
| Services billed to Medicare | 3,443 |
| Different services or procedures | 36 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- Ct guidance for insertion of radiation therapy fields (77014)1,177 services
- Calculation of radiation therapy dose (77300)557 services
- Design and construction of complex radiation treatment device (77334)319 services
- Radiation treatment management, 5 treatment sessions (77427)314 services
- Telephone medical discussion with physician, 5-10 minutes (99441)187 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High blood pressure75%
- High cholesterol75%
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)75%
- Arthritis36%
- Diabetes33%
- Ischemic heart disease29%
Hospitals where William R. Silveira works
Medicare's Facility Affiliation Data lists William R. Silveira at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Clovis Community Medical CenterClovis, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 050492
- Community Regional Medical CenterFresno, CA · Acute Care Hospital · Medicare rating: 1 of 5 stars · Emergency services: listed by Medicare · CCN 050060
Practice locations
Addresses where William R. Silveira is enrolled with Medicare (CMS data updated October 2, 2026). The first 5 of 7; the Medicare profile lists all.
- 2755 Herndon AveClovis, CA 93611 (559) 324‑4000
- 2823 Fresno StFresno, CA 93721 (559) 459‑6000
- 45 E River Park Pl W, Suite 104Fresno, CA 93720 (559) 320‑0530
- 45 E River Park Pl W, Suite 507Fresno, CA 93720
- 785 N Medical Ctr Dr WClovis, CA 93611
Group practices
Medicare enrollment lists William R. Silveira as a member of this group (CMS data updated October 2, 2026).
- Community Health Partners504 clinicians in the group
Specialties
- Radiation Oncologyprimary
Other radiation oncologists in California
Clinicians with the same Medicare primary specialty in California — not a recommendation.
Other clinicians in Community Health Partners
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Harvard Medical School |
| Graduation year | 2009 (17 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1447494398 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians