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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. Aimee Keyashian, MD
Lafayette, CA · $50 in drug and device payments (2025) · Telehealth · (925) 296-7490
Dr. Christopher Simmons, M.D.
Lafayette, CA · $63 in drug and device payments (2025) · Telehealth · (925) 284-4442
Dr. Leonard Saputo, MD
Lafayette, CA · No drug or device payments recorded (2025) · (925) 962-3799
Dr. Maha Toma, M.D.
Lafayette, CA · $1,746 in drug and device payments (2025) · Telehealth · (925) 284-4442
Dr. Roland Schoen, MD
Lafayette, CA · No drug or device payments recorded (2025) · (925) 284-7045
Dr. Vona Wright Lorenzana, M.D.
Lafayette, CA · No drug or device payments recorded (2025) · (925) 324-1391
Dr. Chau Ngo, M.D.
Laguna Beach, CA · $170 in drug and device payments (2025) · (949) 494-0761
Dr. Cherie Hinchliffe, MD
Laguna Beach, CA · No drug or device payments recorded (2025) · (949) 499-2707
Dr. David Kim, MD
Laguna Beach, CA · $677 in drug and device payments (2025) · Telehealth · (949) 499-1339
Dr. Donald Wentzel, MD
Laguna Beach, CA · $7,672 in drug and device payments (2025) · (949) 494-4974
Dr. James Selevan, M.D.
Laguna Beach, CA · No drug or device payments recorded (2025) · (949) 233-1133
Dr. Janne Dewing, M.D.
Laguna Beach, CA · $124 in drug and device payments (2025) · (949) 340-5454
Dr. Jeffrey Crudo, M.D.
Laguna Beach, CA · No drug or device payments recorded (2025) · (949) 715-6890
Dr. Joe Wong, MD
Laguna Beach, CA · No drug or device payments recorded (2025) · (949) 715-0505
Dr. Kathryn Cardoza
Laguna Beach, CA · $217 in drug and device payments (2025) · Telehealth · (949) 557-0610
Dr. Nancy Boerner, M.D.
Laguna Beach, CA · No drug or device payments recorded (2025) · (949) 499-7645
Dr. Rick Pesano, M.D.
Laguna Beach, CA · No drug or device payments recorded (2025) · (949) 637-6750
Dr. Russell Brower, M.D.
Laguna Beach, CA · $29 in drug and device payments (2025) · (949) 315-5528
Dr. Alan Lo, MD
Laguna Hills, CA · $1,457 in drug and device payments (2025) · Telehealth · (949) 768-4850
Dr. Ali Ghahraman, M.D.
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 581-2002
Dr. Ali Ghazvini, M.D.
Laguna Hills, CA · $120 in drug and device payments (2025) · (949) 716-7700
Dr. Allen Jay, M.D
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 362-4560
Dr. Angela Basen, MD
Laguna Hills, CA · $324 in drug and device payments (2025) · Telehealth · (949) 204-3006
Dr. Arthur Daigneault, MD
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 588-8700
Dr. Bijan Movafegh-jooryabi, D.O
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 900-6992
Dr. Brian Henry
Laguna Hills, CA · $77 in drug and device payments (2025) · (949) 588-8700
Dr. Cecilia Tran, MD
Laguna Hills, CA · No drug or device payments recorded (2025) · Telehealth · (949) 420-5980
Dr. Charles Blumberg, MD
Laguna Hills, CA · No drug or device payments recorded (2025) · Telehealth · (949) 238-4100
Dr. Chi-whei Lin, M.D.
Laguna Hills, CA · $316 in drug and device payments (2025) · (949) 716-4555
Dr. Curtis Siu, MD
Laguna Hills, CA · No drug or device payments recorded (2025) · Telehealth · (949) 872-5227
Dr. David Huseby, M.D.
Laguna Hills, CA · No drug or device payments recorded (2025) · Telehealth · (949) 373-7799
Dr. David Nah, DO
Laguna Hills, CA · $46 in drug and device payments (2025) · (949) 362-8877
Dr. David Teng, MD
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 799-4786
Dr. Dzintris Vallis, MD
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 334-8200
Dr. Ester Mark, M.D.
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 903-8563
Dr. Farbod Farmand, D.O
Laguna Hills, CA · $1,632 in drug and device payments (2025) · (949) 555-5555
Dr. Gregory Lam, M.D.
Laguna Hills, CA · $19 in drug and device payments (2025) · Telehealth · (949) 238-4100
Dr. Homer Lew, D.O.
Laguna Hills, CA · $290 in drug and device payments (2025) · (949) 588-7262
Dr. Humberto Boccardo, M.D.
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 951-7808
Dr. Hussien Saab, MD
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 215-5055
Dr. Jason Hunt, D.O.
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 768-4850
Dr. Julie Marshburn, M.D.
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 768-4850
Dr. Konidala Naidu, MD
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 770-7907
Dr. Lawrence Luppi, M.D.
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 206-0360
Dr. Lori Clark
Laguna Hills, CA · $182 in drug and device payments (2025) · (949) 588-7262
Dr. Louis Scarcella, MD
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 770-7691
Dr. Lynn Granlund, M. D.
Laguna Hills, CA · No drug or device payments recorded (2025) · (949) 373-7799
Dr. Mark Shields, MD
Laguna Hills, CA · No drug or device payments recorded (2025) · Telehealth · (949) 588-8700
Dr. Marwan Edris, M.D.
Laguna Hills, CA · $22 in drug and device payments (2025) · (949) 364-9080
Dr. Maziar Zamani, M.D.
Laguna Hills, CA · No drug or device payments recorded (2025) · Telehealth · (949) 404-5647

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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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.