Internal Medicine in Fontana, California
Data updated monthly · Last refresh September 2026
111 Internal Medicine providers practice in Fontana, and 15% received drug or device company payments in 2025. Listings are drawn from federal public records and are not endorsements.
Internal Medicine providers in Fontana
Listed alphabetically. Payment figures come from the federal Open Payments program, which requires drug and device companies to report what they pay physicians for consulting, speaking, meals, travel and royalties. A disclosed payment is a financial relationship, not evidence of wrongdoing, and many totals reflect a single meal. Figures cover calendar year 2025.
Dr. Syed Yusuf, M.D.Fontana, CA · No drug or device payments recorded (2025) ·
(833) 574-2273 Dr. Te-ie Lee, M.D.Fontana, CA · No drug or device payments recorded (2025) ·
(909) 427-5310 Dr. Tim Shen, M.D.Fontana, CA · $200 in drug and device payments (2025) ·
(909) 427-4873 Dr. Tin Nguyen, MDFontana, CA · $36 in drug and device payments (2025) · Telehealth ·
(909) 427-3910 Dr. Usha Raghavan, MDFontana, CA · No drug or device payments recorded (2025) ·
(909) 427-3917 Dr. Wan Cheng Yeap, M.D.Fontana, CA · No drug or device payments recorded (2025) ·
(617) 823-8457 Dr. Wei Chan Hwang, M.D.Fontana, CA · No drug or device payments recorded (2025) ·
(909) 427-2673 Dr. William Lai, MDFontana, CA · No drug or device payments recorded (2025) ·
(909) 427-5000 Dr. Xu He, D.OFontana, CA · $82,672 in drug and device payments (2025) · Telehealth ·
(909) 823-8000 Dr. Yang Li, D.O.Fontana, CA · No drug or device payments recorded (2025) ·
(888) 750-0036 Dr. Yeo Youn, MDFontana, CA · No drug or device payments recorded (2025) ·
(909) 427-3910 Conditions Internal Medicine providers in Fontana, California commonly treat
Patients often search by condition rather than specialty. These are conditions typically managed by Internal Medicine providers. Individual practices vary, so confirm with the provider before booking.
- High blood pressure
- Type 2 diabetes
- High cholesterol
- Preventive care
- Chronic disease management
Common questions
How many Internal Medicine providers are in Fontana, California?There are 111 Internal Medicine providers with active NPI records practicing in Fontana, according to federal NPPES data refreshed monthly.
How many Internal Medicine providers in Fontana received drug or device company payments?17 of 111 (15%) received at least one payment from a drug or device company in 2025, according to the federal Open Payments program.
What conditions do Internal Medicine providers in Fontana treat?Internal Medicine providers in Fontana commonly treat high blood pressure, type 2 diabetes, high cholesterol, preventive care, chronic disease management and related conditions. Individual practices vary, so confirm with the provider before booking.
Where does this data come from?Provider records come from the federal NPPES registry and CMS Doctors and Clinicians files. Payment figures come from the CMS Open Payments program for calendar year 2025. The directory refreshes monthly.
All specialties in Fontana Internal Medicine across California
