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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. Gwendolyn Gore, MD
Rancho Santa Margarita, CA · No drug or device payments recorded (2025) · Telehealth · (949) 459-9968
Dr. Iwan Nyotowidjojo, M.D.
Rancho Santa Margarita, CA · $55 in drug and device payments (2025) · (949) 459-9968
Dr. Lilian Tran, MD
Rancho Santa Margarita, CA · $159 in drug and device payments (2025) · Telehealth · (949) 459-9968
Dr. Siamak Zamani, M.D.
Rancho Santa Margarita, CA · No drug or device payments recorded (2025) · (949) 589-9114
Dr. Sridhar Kundula, M.D.
Rancho Santa Margarita, CA · No drug or device payments recorded (2025) · (949) 459-4820
Dr. Andrew Pomazal, DO
Red Bluff, CA · No drug or device payments recorded (2025) · (530) 528-2066
Dr. Arjana Shakya, MD
Red Bluff, CA · No drug or device payments recorded (2025) · (530) 527-0414
Dr. David Dahnke
Red Bluff, CA · No drug or device payments recorded (2025) · (530) 527-0414
Dr. Faisal Kanbar-agha, MD
Red Bluff, CA · No drug or device payments recorded (2025) · Telehealth · (530) 528-4430
Dr. Giang Bui
Red Bluff, CA · $103 in drug and device payments (2025) · (530) 529-8000
Dr. Jaimal Johal, MD
Red Bluff, CA · $278 in drug and device payments (2025) · (530) 529-8000
Dr. Kerry Waits, D.O.
Red Bluff, CA · $345 in drug and device payments (2025) · (530) 529-8330
Dr. Lisa Cheung
Red Bluff, CA · $40 in drug and device payments (2025) · (530) 527-0414
Dr. Natasha Maqsood, MD
Red Bluff, CA · $17 in drug and device payments (2025) · (832) 312-0496
Dr. Neil Louwrens, M.D.
Red Bluff, CA · $321 in drug and device payments (2025) · Telehealth · (888) 633-1441
Dr. Richard Wickenheiser, MD
Red Bluff, CA · No drug or device payments recorded (2025) · (530) 527-0414
Dr. Saeid Ahmadpour, MD
Red Bluff, CA · No drug or device payments recorded (2025) · (530) 527-0414
Dr. Zubin Udwadia, MD
Red Bluff, CA · No drug or device payments recorded (2025) · (530) 529-8000
Dr. Andrea Hsue, M.D.
Redding, CA · No drug or device payments recorded (2025) · (530) 246-5908
Dr. Brandon Penn, D.O.
Redding, CA · No drug or device payments recorded (2025) · (530) 244-2223
Dr. Brian Hearney, MD
Redding, CA · No drug or device payments recorded (2025) · (530) 226-7540
Dr. Carolyn Lintner, M.D.
Redding, CA · No drug or device payments recorded (2025) · (530) 246-5710
Dr. Corsini Templado, M.D.
Redding, CA · No drug or device payments recorded (2025) · (530) 226-7555
Dr. Dinesh Mantri, MD
Redding, CA · No drug or device payments recorded (2025) · (530) 768-4052
Dr. Elaine Hearney, MD
Redding, CA · No drug or device payments recorded (2025) · (530) 226-7555
Dr. Fernando Alvarez, M.D.
Redding, CA · No drug or device payments recorded (2025) · (530) 242-4682
Dr. Gary Crawford, MD
Redding, CA · No drug or device payments recorded (2025) · (530) 941-1583
Dr. Gisela Okonski, M.D.
Redding, CA · $1,124 in drug and device payments (2025) · (530) 247-0404
Dr. Gurpreet Sandhoo, D.O.,PH.D
Redding, CA · $157 in drug and device payments (2025) · (530) 243-1414
Dr. James Hardy, M.D.
Redding, CA · No drug or device payments recorded (2025) · (530) 243-1534
Dr. Jennifer Spurlock, M.D.
Redding, CA · $136 in drug and device payments (2025) · Telehealth · (530) 242-3590
Dr. Kaushik Patel, M.D.
Redding, CA · $17 in drug and device payments (2025) · (530) 242-4683
Dr. Kevin Rainsford, M.D.
Redding, CA · $317 in drug and device payments (2025) · (530) 246-9000
Dr. Khalid Mahmood
Redding, CA · $234 in drug and device payments (2025) · (530) 244-5400
Dr. Khin Aung, M.D
Redding, CA · No drug or device payments recorded (2025) · (530) 225-6000
Dr. Koteshwareddy Vadagandla, M.D
Redding, CA · $98 in drug and device payments (2025) · (530) 244-8250
Dr. Lawrence Bratt, MD
Redding, CA · No drug or device payments recorded (2025) · (530) 226-7509
Dr. Lily Jamm, M.D.
Redding, CA · No drug or device payments recorded (2025) · (530) 247-7234
Dr. Louis Bernstein, M.D.
Redding, CA · No drug or device payments recorded (2025) · (530) 638-8951
Dr. Maria Gove, MD
Redding, CA · No drug or device payments recorded (2025) · (530) 226-7555
Dr. Mark Pierce, M.D.
Redding, CA · No drug or device payments recorded (2025) · (530) 221-1565
Dr. Matthew Peltz, D.O.
Redding, CA · No drug or device payments recorded (2025) · (530) 229-1310
Dr. Nelson De Guzman, MD
Redding, CA · No drug or device payments recorded (2025) · (530) 226-7524
Dr. Olivia Mansilla, MD
Redding, CA · $558 in drug and device payments (2025) · (804) 301-0225
Dr. Regis Britto, MD
Redding, CA · $423 in drug and device payments (2025) · (530) 241-9450
Dr. Renu Magu, M.D.
Redding, CA · $91 in drug and device payments (2025) · (702) 453-3799
Dr. Sara Choudhry, M.D.
Redding, CA · No drug or device payments recorded (2025) · (530) 246-5721
Dr. Sethu Sandeep Koneru, MD
Redding, CA · $251 in drug and device payments (2025) · Telehealth · (530) 605-4263
Dr. Sheralene Ng, MD
Redding, CA · $180 in drug and device payments (2025) · Telehealth · (530) 242-3590
Dr. Stephen Casey, M.D.
Redding, CA · $29 in drug and device payments (2025) · (530) 243-3288

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.