Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

William Sun

Individual provider Internal Medicine Physician · NPI 1649777616

William Sun practises Internal Medicine in Fresno, California. Qualified in 2018, 8 years ago. Practices with Galen Inpatient Physicians PC, a 1,031-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
8
Licensed in
CA
In the registry since
2018
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Practice location Address checks out

155 N Fresno St
Fresno, CA 93701-2302
Phone: (559) 499-6500
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence A174650 (CA)

Record details

NPI number1649777616
Entity typeIndividual (Type 1)
GenderMale
Sole proprietorNo
NPI enumeratedApril 6, 2018
Last updated in NPPESFebruary 2, 2022
Certification dateFebruary 2, 2022

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyINTERNAL MEDICINE
Medical schoolOTHER
Graduated 2018 (8 years in practice)
Group practice Galen Inpatient Physicians Pc — 1031 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations3 on file with Medicare

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients62
Services billed 181 a service is one billed item, such as a visit, a test or a procedure
Average patient age80

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $27 1 payment · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

  • Adventist Health Simi Valley Hospital · Simi Valley, CA · listed as Simi Valley Hospital & Health Care Services
  • Santa Clara Valley Medical Center Hospital · San Jose, CA
  • Adventist Health Sierra Vista Hospital · San Luis Obispo, CA
  • Adventist Health Twin Cities Hospital · Templeton, CA
  • Emanate Health Inter-Community Hospital Hospital · Covina, CA

Colleagues at Galen Inpatient Physicians PC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 1031 clinicians in the practice; 12 are shown here.

Other providers in Fresno