Patricia C. Hsia, MD

Practice locations

Addresses where Patricia C. Hsia is enrolled with Medicare (CMS data updated October 2, 2026).

• 2295 S Vineyard AveOntario, CA 91761 (909) 724‑5000
• 9961 Sierra AveFontana, CA 92335 (909) 427‑5000

Group practices

Medicare enrollment lists Patricia C. Hsia as a member of this group (CMS data updated October 2, 2026).

• Southern California Permanente Medical Group11,293 clinicians in the group

Specialties

• Internal Medicineprimary
• Gastroenterologyalso

Find other Internal Medicine doctors in California →

Other internal medicine doctors in Ontario

Clinicians with the same Medicare primary specialty in Ontario, CA — not a recommendation.

• Dien T. Ton-That, DO
• Dat Ha, DO
• Deanna C. Lo, MD
• Johnathan Chou, MD
• Elnaz Rakhshan, MD
• Moemen A. Khattab, MD
• Linh N. Truong, MD
• Edward U. Oh, MD

All internal medicine doctors in Ontario →

Other clinicians in Southern California Permanente Medical Group

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

• Rick C. Wang, OD
• William K. Kim, MD
• Diana I. Bernal, CNA
• Agnes E. Chen, DO
• Azadeh Nazemi, MD
• Kevin F. Myerly, MD

Clinician information

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

1. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
2. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
3. Medicare Care Compare — official Medicare tool to look up clinicians