Oncologists in California
Data updated monthly · Last refresh October 2026
450 Medical Oncology providers practice in California, including 271 (60%) offering telehealth. The largest concentration is in Stanford. 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.
450providers
271telehealth
Stanfordtop city
Medical Oncology by city in California
Choose a city to see providers there.
Medical 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. Seung-yil Song, M.D.San Diego, CA · $3,991 in drug and device payments (2025) ·
(858) 571-2811 Dr. Siddharth Iyengar, MDSan Diego, CA · $630 in drug and device payments (2025) ·
(800) 926-8273 Dr. Tanim Jain, MDSan Diego, CA · No drug or device payments recorded (2025) ·
(800) 926-8273 Dr. Wenji Guo, MDSan Diego, CA · No drug or device payments recorded (2025) ·
(800) 926-8273 Dr. Xiaojie ZhangSan Diego, CA · No drug or device payments recorded (2025) · Telehealth ·
(800) 926-8273 Dr. Alan Kramer, MDSan Francisco, CA · $3,712 in drug and device payments (2025) · Telehealth ·
(415) 885-8600 Dr. Alan Newman, MDSan Francisco, CA · No drug or device payments recorded (2025) ·
(415) 885-8600 Dr. Alan Venook, MDSan Francisco, CA · $125 in drug and device payments (2025) ·
(415) 353-9888 Dr. Aman Chauhan, MDSan Francisco, CA · $33,351 in drug and device payments (2025) · Telehealth ·
(415) 353-9888 Dr. Amy Chien, M.D.San Francisco, CA · $7,094 in drug and device payments (2025) · Telehealth ·
(415) 353-7070 Dr. Ana Velazquez, MD MSCSan Francisco, CA · $46,811 in drug and device payments (2025) · Telehealth ·
(628) 206-2406 Dr. Andrew Ko, MDSan Francisco, CA · $21,744 in drug and device payments (2025) · Telehealth ·
(415) 353-9888 Dr. Bridget KeenanSan Francisco, CA · $184 in drug and device payments (2025) · Telehealth ·
(415) 476-1528 Dr. Charles Dollbaum, M.D.San Francisco, CA · No drug or device payments recorded (2025) · Telehealth ·
(415) 353-7070 Dr. Chloe Atreya, MD, PHDSan Francisco, CA · No drug or device payments recorded (2025) · Telehealth ·
(415) 353-9888 Dr. Christopher Benz, M.D.San Francisco, CA · No drug or device payments recorded (2025) ·
(415) 353-7070 Dr. David Minor, MDSan Francisco, CA · No drug or device payments recorded (2025) ·
(415) 885-8600 Dr. Divneet Mandair, MSSan Francisco, CA · No drug or device payments recorded (2025) · Telehealth ·
(415) 476-4562 Dr. Donald Abrams, MDSan Francisco, CA · No drug or device payments recorded (2025) · Telehealth ·
(415) 353-7720 Dr. Edward Cha, M.D.San Francisco, CA · No drug or device payments recorded (2025) ·
(415) 885-7276 Dr. Emily Bergsland, MDSan Francisco, CA · $96 in drug and device payments (2025) · Telehealth ·
(415) 353-9888 Dr. Evan WalkerSan Francisco, CA · No drug or device payments recorded (2025) · Telehealth ·
(415) 476-1528 Dr. Garrett Smith, M.D.San Francisco, CA · No drug or device payments recorded (2025) ·
(415) 682-0843 Dr. Gerald Hsu, MDSan Francisco, CA · No drug or device payments recorded (2025) ·
(415) 885-7467 Dr. Guus Bol, MD, PHDSan Francisco, CA · $87 in drug and device payments (2025) · Telehealth ·
(415) 353-3000 Dr. Hemali Batra-sharma, MDSan Francisco, CA · $98 in drug and device payments (2025) · Telehealth ·
(415) 353-7070 Dr. Ivan De KouchkovskySan Francisco, CA · $1,460 in drug and device payments (2025) · Telehealth ·
(415) 476-1529 Dr. James Rubenstein, MDSan Francisco, CA · $21 in drug and device payments (2025) · Telehealth ·
(415) 353-2421 Dr. Jennifer Schutzman, MDSan Francisco, CA · No drug or device payments recorded (2025) ·
(415) 353-7171 Dr. John Berry, M.D.San Francisco, CA · $48 in drug and device payments (2025) ·
(415) 353-7100 Dr. John Park, MDSan Francisco, CA · $124,017 in drug and device payments (2025) · Telehealth ·
(415) 353-7070 Dr. Judith Luce, MDSan Francisco, CA · No drug or device payments recorded (2025) ·
(415) 476-4082 Dr. Kapil Saxena, M.D.San Francisco, CA · No drug or device payments recorded (2025) ·
(415) 353-7900 Dr. Katherine Vanloon, MD MPHSan Francisco, CA · No drug or device payments recorded (2025) · Telehealth ·
(415) 353-9888 Dr. Kelly Fitzgerald, MDSan Francisco, CA · $511 in drug and device payments (2025) · Telehealth ·
(415) 476-1528 Dr. Kelsey Natsuhara, MDSan Francisco, CA · $2,113 in drug and device payments (2025) · Telehealth ·
(415) 353-7070 Dr. Kevin Kim, M.D.San Francisco, CA · $25,783 in drug and device payments (2025) · Telehealth ·
(415) 885-8600 Dr. Kristen Hege, MDSan Francisco, CA · $14,198 in drug and device payments (2025) ·
(415) 353-2421 Dr. Laura Huppert, M.D.San Francisco, CA · $13,693 in drug and device payments (2025) · Telehealth ·
(415) 353-7070 Dr. Lawrence Kaplan, MDSan Francisco, CA · No drug or device payments recorded (2025) · Telehealth ·
(415) 353-2421 Dr. Lloyd Damon, MDSan Francisco, CA · No drug or device payments recorded (2025) · Telehealth ·
(415) 353-2421 Dr. Luai Al Rabadi, M.D.San Francisco, CA · No drug or device payments recorded (2025) · Telehealth ·
(415) 353-9888 Dr. Margaret Guo, MD, PHDSan Francisco, CA · No drug or device payments recorded (2025) ·
(415) 476-1000 Dr. Mark Moasser, M.D.San Francisco, CA · No drug or device payments recorded (2025) · Telehealth ·
(415) 353-7070 Dr. Melisa Yajima, MDSan Francisco, CA · No drug or device payments recorded (2025) ·
(415) 885-3882 Dr. Michael Cheng, MDSan Francisco, CA · $4,630 in drug and device payments (2025) · Telehealth ·
(415) 885-3882 Dr. Michelle Melisko, MDSan Francisco, CA · $875 in drug and device payments (2025) · Telehealth ·
(415) 353-7070 Dr. Natalie Sacks, M.D.San Francisco, CA · No drug or device payments recorded (2025) ·
(415) 476-4082 Dr. Robert Bok, MD, PHDSan Francisco, CA · No drug or device payments recorded (2025) ·
(415) 514-9716 Dr. Rohit Bose, M.D., PH.D.San Francisco, CA · $7,720 in drug and device payments (2025) · Telehealth ·
(415) 476-4616 Common questions
How many Medical Oncology providers are in California?There are 450 Medical Oncology providers with active NPI records practicing in California, according to federal NPPES data refreshed monthly.
Do Medical Oncology providers in California offer telehealth?Yes. 271 of the 450 Medical Oncology providers in California (about 60%) report offering telehealth services in CMS data.
Which cities in California have the most Medical Oncology providers?Stanford (83), San Francisco (54), Duarte (49) have the highest concentration of Medical Oncology providers in California.
How many Medical Oncology providers in California received drug or device company payments?281 of 450 Medical Oncology providers in California (62%) 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 Oncologists in California work in independent practices or large health systems?Among 313 Oncologists in California enrolled in Medicare, 7% bill through a solo or small practice with fewer than 10 clinicians, 4% through a mid-size group of 10 to 99, and 88% through a large group or health system with 100 or more clinicians, according to CMS enrollment records.
Which hospitals do Oncologists in California work at?According to CMS facility affiliation records, the California hospitals where the most Oncologists hold privileges are Stanford Health Care in Stanford; UCSF Medical Center in San Francisco; Stanford Health Care Tri-Valley in Pleasanton.
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