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Internal Medicine Doctors in California

Data updated monthly · Last refresh October 2026

17,715 Internal Medicine providers practice in California, including 4,245 (24%) offering telehealth. The largest concentration is in Los Angeles. Profiles include federal Open Payments records of money received from drug and device companies in 2025. Listings are drawn from federal public records and are not endorsements.

17,715providers
4,245telehealth
Los Angelestop city

Internal Medicine by city in California

Choose a city to see providers there.

Internal Medicine in Los Angeles1,417 providers
Internal Medicine in San Francisco1,322 providers
Internal Medicine in San Diego970 providers
Internal Medicine in Sacramento602 providers
Internal Medicine in Oakland434 providers
Internal Medicine in San Jose433 providers
Internal Medicine in Stanford383 providers
Internal Medicine in Fresno339 providers
Internal Medicine in Torrance230 providers
Internal Medicine in Long Beach225 providers
Internal Medicine in Bakersfield210 providers
Internal Medicine in Loma Linda209 providers
Internal Medicine in Palo Alto189 providers
Internal Medicine in Anaheim188 providers
Internal Medicine in Orange188 providers
Internal Medicine in Riverside188 providers
Internal Medicine in Walnut Creek184 providers
Internal Medicine in Santa Monica170 providers
Internal Medicine in La Jolla161 providers
Internal Medicine in Roseville159 providers
Internal Medicine in Irvine155 providers
Internal Medicine in Beverly Hills152 providers
Internal Medicine in Santa Clara142 providers
Internal Medicine in Pasadena138 providers

Internal Medicine providers in California

Listed by city, largest first. 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. Hoveda Mufti, M.D.
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-5000
Dr. James Morgenstern, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. James Setiawan, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Jasmit Dhaliwal, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. J Duc Nguyen, M.D.
Fontana, CA · No drug or device payments recorded (2025) · (909) 822-1164
Dr. Joe Wohlmuth, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. John Uniat, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Jonahlie Quintos-monsale, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-7032
Dr. Jonathan Lo, MD
Fontana, CA · $141 in drug and device payments (2025) · (909) 427-3910
Dr. Joseph Paredes, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Joyce Taur, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Julie Reddoch, M.D.
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-5000
Dr. Kanchana Keerthipala, M.D.
Fontana, CA · No drug or device payments recorded (2025) · (909) 904-6589
Dr. Kareem Yahya, MD
Fontana, CA · No drug or device payments recorded (2025) · (833) 574-2273
Dr. Katherine Lin, D.O.
Fontana, CA · No drug or device payments recorded (2025) · (909) 839-1912
Dr. Les Liu, MD
Fontana, CA · No drug or device payments recorded (2025) · Telehealth · (909) 427-3910
Dr. Lev Rasin, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Lih-jiau Chen, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Lilybeth Sistoza, MD
Fontana, CA · $40 in drug and device payments (2025) · (909) 428-3900
Dr. Loan Pham, MD
Fontana, CA · $124 in drug and device payments (2025) · (909) 427-3910
Dr. Loi Tran, DO
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Lydia Villanueva, M.D.
Fontana, CA · No drug or device payments recorded (2025) · (909) 822-1164
Dr. Manuel Mojica, M.D.
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-5000
Dr. Margaret Mou, DO
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Maria Relente-santos, MD
Fontana, CA · $166 in drug and device payments (2025) · (909) 823-8000
Dr. Mario Perez, D.O.
Fontana, CA · No drug or device payments recorded (2025) · Telehealth · (909) 427-3077
Dr. Mark Eicher, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Melanie Wise, MD
Fontana, CA · No drug or device payments recorded (2025) · (833) 574-2273
Dr. Michael Chen, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Michael Lee, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Muhammad Khan, M.D.
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-5000
Dr. Nasser Liasi, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-1303
Dr. Neha Pandey, M.D.
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-5500
Dr. Paloma Khamly
Fontana, CA · No drug or device payments recorded (2025) · (323) 409-6566
Dr. Pamela Yamanishi, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Paul Kim, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Paul Robb, M.D.
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-5000
Dr. Philomena Cho, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Pooneh Esfahani, DO
Fontana, CA · No drug or device payments recorded (2025) · Telehealth · (909) 427-3910
Dr. Prasit Vassantachart, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Ragu Sivarajan, D.O,.
Fontana, CA · No drug or device payments recorded (2025) · (909) 330-3939
Dr. Ramesh Patel, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 822-1403
Dr. Robert Liu
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-5000
Dr. Rofina Widjaja, MD
Fontana, CA · No drug or device payments recorded (2025) · Telehealth · (909) 427-3910
Dr. Ruperto Mendiones, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Samuel Paw, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Sanjay Bhakta, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Scott Wojtowich, DO
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Sean Khorami, M.D.
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-2608
Dr. Sherilyn Savery, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910

Conditions Internal Medicine providers in 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.

Common questions

How many Internal Medicine providers are in California?

There are 17,715 Internal Medicine providers with active NPI records practicing in California, according to federal NPPES data refreshed monthly.

Do Internal Medicine providers in California offer telehealth?

Yes. 4,245 of the 17,715 Internal Medicine providers in California (about 24%) report offering telehealth services in CMS data.

Which cities in California have the most Internal Medicine providers?

Los Angeles (1,417), San Francisco (1,322), San Diego (970) have the highest concentration of Internal Medicine providers in California.

How many Internal Medicine providers in California received drug or device company payments?

5,614 of 17,715 Internal Medicine providers in California (32%) 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 California treat?

Internal Medicine providers 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 counts and profiles 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.

Do most Internal Medicine Doctors in California work in independent practices or large health systems?

Among 10,847 Internal Medicine Doctors in California enrolled in Medicare, 20% bill through a solo or small practice with fewer than 10 clinicians, 12% through a mid-size group of 10 to 99, and 67% through a large group or health system with 100 or more clinicians, according to CMS enrollment records.

Which hospitals do Internal Medicine Doctors in California work at?

According to CMS facility affiliation records, the California hospitals where the most Internal Medicine Doctors hold privileges are Stanford Health Care in Stanford; UCSF Medical Center in San Francisco; Ronald Reagan UCLA Medical Center in Los Angeles.

Related reading on HealthcareDiscovery.AI

Internal Medicine in all 50 states Search all 17,715 in the directory Ask Zach for help choosing

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Try a city like Tucson, a zip like 85016, or a specialty like psychiatry. For a doctor by name, use the full search.
Sources: NPPES (CMS), Doctors and Clinicians national files, CMS Open Payments 2025. Updated monthly. Records are public federal data and are not verified credentials, licensure checks, or endorsements. This directory is informational and not medical advice. How we build this directory. Are you a Internal Medicine in California? Get featured.