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Radiation Oncologists in California

Data updated monthly · Last refresh October 2026

734 Radiation Oncology providers practice in California, including 310 (42%) 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.

734providers
310telehealth
Los Angelestop city

Radiation Oncology by city in California

Choose a city to see providers there.

Radiation Oncology in Los Angeles97 providers
Radiation Oncology in San Francisco46 providers
Radiation Oncology in Stanford43 providers
Radiation Oncology in San Diego43 providers
Radiation Oncology in Sacramento32 providers
Radiation Oncology in Orange19 providers
Radiation Oncology in Duarte16 providers
Radiation Oncology in La Jolla15 providers
Radiation Oncology in Palo Alto14 providers
Radiation Oncology in San Jose11 providers
Radiation Oncology in Loma Linda11 providers
Radiation Oncology in West Hollywood10 providers
Radiation Oncology in Fresno9 providers
Radiation Oncology in Santa Clara9 providers
Radiation Oncology in Long Beach9 providers
Radiation Oncology in Redding8 providers
Radiation Oncology in Fountain Valley7 providers
Radiation Oncology in Santa Barbara7 providers
Radiation Oncology in Dublin7 providers
Radiation Oncology in Torrance7 providers
Radiation Oncology in Irvine7 providers
Radiation Oncology in Chula Vista6 providers
Radiation Oncology in Newport Beach6 providers
Radiation Oncology in Oakland6 providers

Radiation Oncology 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. Ramesh Gadam, M.D.
Mountain View, CA · $176 in drug and device payments (2025) · (650) 940-7280
Dr. Robert Sinha, MD
Mountain View, CA · No drug or device payments recorded (2025) · Telehealth · (650) 940-7280
Dr. Shahil Mehta, MD
Mountain View, CA · $3,128 in drug and device payments (2025) · Telehealth · (650) 940-7280
Dr. Stephen Weller, MD
Mountain View, CA · No drug or device payments recorded (2025) · (650) 934-7000
Dr. Bhavani Gannavarapu, M.D.
Napa, CA · $57 in drug and device payments (2025) · Telehealth · (707) 252-4411
Dr. Christian Anderson, M.D.
Napa, CA · No drug or device payments recorded (2025) · (707) 252-4633
Dr. James Knister, M.D.
Napa, CA · No drug or device payments recorded (2025) · (707) 252-4633
Dr. Patricia Seid, MD
Napa, CA · $2,102 in drug and device payments (2025) · Telehealth · (707) 252-4411
Dr. Brian Kim, MD
Newport Beach, CA · $164 in drug and device payments (2025) · Telehealth · (949) 764-5528
Dr. Craig Cox, MD
Newport Beach, CA · No drug or device payments recorded (2025) · Telehealth · (949) 764-5528
Dr. Kevin Lin, M.D.
Newport Beach, CA · $49 in drug and device payments (2025) · Telehealth · (949) 764-5528
Dr. Peter Chen, MD
Newport Beach, CA · $144 in drug and device payments (2025) · Telehealth · (949) 764-5528
Dr. Shane Lloyd, M.D., PH.D.
Newport Beach, CA · No drug or device payments recorded (2025) · Telehealth · (949) 764-5528
Dr. Stephen Doggett, M.D.
Newport Beach, CA · $29,125 in drug and device payments (2025) · Telehealth · (949) 490-4820
Dr. Mark Rounsaville, MD
Nicasio, CA · No drug or device payments recorded (2025) · (415) 662-2669
Dr. Mary Denk, M.D.
North Hollywood, CA · No drug or device payments recorded (2025) · (818) 769-6378
Dr. Charles Fiske, M.D.
Oakland, CA · No drug or device payments recorded (2025) · (925) 274-4950
Dr. Jason Kelly, MD
Oakland, CA · No drug or device payments recorded (2025) · (510) 752-1000
Dr. John Salzman, MD
Oakland, CA · $53 in drug and device payments (2025) · (931) 432-2343
Dr. Matthew Susko, M.D.
Oakland, CA · No drug or device payments recorded (2025) · Telehealth · (415) 308-5813
Dr. Michael Faer, M.D.
Oakland, CA · No drug or device payments recorded (2025) · (925) 274-4950
Dr. Trang La, MD
Oakland, CA · No drug or device payments recorded (2025) · (510) 752-1000
Dr. Dong Kim, M.D., PH.D.
Ontario, CA · $28 in drug and device payments (2025) · (909) 724-2020
Dr. Aaron Simon, MD, PHD
Orange, CA · $10,099 in drug and device payments (2025) · Telehealth · (714) 456-8074
Dr. Allen Chen, M.D.
Orange, CA · $1,260 in drug and device payments (2025) · (714) 880-7812
Dr. Caressa Hui, MD
Orange, CA · $119 in drug and device payments (2025) · Telehealth · (714) 456-8888
Dr. Christina Abel, NURSE PRACTITIONER
Orange, CA · $362 in drug and device payments (2025) · (714) 734-6256
Dr. Eric Chen, MD
Orange, CA · $119 in drug and device payments (2025) · Telehealth · (657) 579-3129
Dr. Erin Healy, MD
Orange, CA · $62 in drug and device payments (2025) · Telehealth · (714) 880-7812
Dr. Garrett Harada, MD
Orange, CA · No drug or device payments recorded (2025) · Telehealth · (714) 456-8000
Dr. Jason Wong, MD
Orange, CA · No drug or device payments recorded (2025) · (714) 456-5651
Dr. Jeffrey Kuo, MD
Orange, CA · No drug or device payments recorded (2025) · (714) 456-8978
Dr. Jeremy Harris, MD
Orange, CA · No drug or device payments recorded (2025) · Telehealth · (714) 456-8095
Dr. Jino Park, MD
Orange, CA · No drug or device payments recorded (2025) · (714) 456-5651
Dr. Krishna Hanubal, MD
Orange, CA · No drug or device payments recorded (2025) · (714) 456-8000
Dr. Megan Daly, M.D.
Orange, CA · $10,308 in drug and device payments (2025) · Telehealth · (714) 456-8888
Dr. Robert Ash, MD
Orange, CA · $280 in drug and device payments (2025) · (714) 734-6250
Dr. Robert Hesselgesser, MD
Orange, CA · $90 in drug and device payments (2025) · (714) 880-7812
Dr. Shera Feinstein, MD
Orange, CA · No drug or device payments recorded (2025) · Telehealth · (714) 456-8888
Dr. Steven Davis, M.D.
Orange, CA · No drug or device payments recorded (2025) · Telehealth · (714) 880-7812
Dr. Tanuja Bhandari, MD
Orange, CA · $52 in drug and device payments (2025) · (714) 734-6250
Dr. Venita Williams, MD
Orange, CA · $214 in drug and device payments (2025) · (714) 734-6250
Dr. Thomas Guerrero, MD, PHD
Oroville, CA · No drug or device payments recorded (2025) · Telehealth · (530) 538-5600
Dr. Henry Montes, M.D.
Oxnard, CA · No drug or device payments recorded (2025) · (805) 988-2657
Dr. Robert Lum, M.D.
Oxnard, CA · $87 in drug and device payments (2025) · (805) 485-2824
Dr. Timothy Oconnor, M.D.
Oxnard, CA · $63 in drug and device payments (2025) · (805) 988-2657
Dr. Artour Torossian, M.D.
Palmdale, CA · $105 in drug and device payments (2025) · (661) 729-2316
Dr. Yuchi Peng, MD
Palmdale, CA · $74 in drug and device payments (2025) · (661) 729-2316
Dr. Perry Zong, MD
Palm Desert, CA · $342 in drug and device payments (2025) · Telehealth · (760) 368-2000
Dr. Peter Greenberg, MD
Palm Desert, CA · $371 in drug and device payments (2025) · (760) 200-8777

Common questions

How many Radiation Oncology providers are in California?

There are 734 Radiation Oncology providers with active NPI records practicing in California, according to federal NPPES data refreshed monthly.

Do Radiation Oncology providers in California offer telehealth?

Yes. 310 of the 734 Radiation Oncology providers in California (about 42%) report offering telehealth services in CMS data.

Which cities in California have the most Radiation Oncology providers?

Los Angeles (97), San Francisco (46), Stanford (43) have the highest concentration of Radiation Oncology providers in California.

How many Radiation Oncology providers in California received drug or device company payments?

359 of 734 Radiation Oncology providers in California (49%) received at least one payment from a drug or device company in 2025, according to the federal Open Payments program.

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 Radiation Oncologists in California work in independent practices or large health systems?

Among 516 Radiation Oncologists in California enrolled in Medicare, 16% bill through a solo or small practice with fewer than 10 clinicians, 17% 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 Radiation Oncologists in California work at?

According to CMS facility affiliation records, the California hospitals where the most Radiation Oncologists hold privileges are UCSF Medical Center in San Francisco; Stanford Health Care in Stanford; UC San Diego Health Hillcrest - Hillcrest Med Ctr in San Diego.

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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 Radiation Oncology in California? Get featured.