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Hematologists and Oncologists in California

Data updated monthly · Last refresh October 2026

1,582 Hematology & Oncology providers practice in California, including 855 (54%) 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.

1,582providers
855telehealth
Los Angelestop city

Hematology & Oncology by city in California

Choose a city to see providers there.

Hematology & Oncology in Los Angeles152 providers
Hematology & Oncology in San Diego89 providers
Hematology & Oncology in Sacramento77 providers
Hematology & Oncology in San Francisco64 providers
Hematology & Oncology in Orange62 providers
Hematology & Oncology in La Jolla46 providers
Hematology & Oncology in Santa Monica43 providers
Hematology & Oncology in Torrance33 providers
Hematology & Oncology in Fresno31 providers
Hematology & Oncology in Stanford30 providers
Hematology & Oncology in Walnut Creek23 providers
Hematology & Oncology in Newport Beach21 providers
Hematology & Oncology in Rancho Mirage19 providers
Hematology & Oncology in Long Beach18 providers
Hematology & Oncology in Roseville17 providers
Hematology & Oncology in Fountain Valley17 providers
Hematology & Oncology in Beverly Hills16 providers
Hematology & Oncology in Santa Barbara16 providers
Hematology & Oncology in San Jose15 providers
Hematology & Oncology in Oakland14 providers
Hematology & Oncology in Downey14 providers
Hematology & Oncology in Anaheim14 providers
Hematology & Oncology in Irvine13 providers
Hematology & Oncology in Santa Rosa13 providers

Hematology & 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. Lasika Seneviratne, M.D.
Los Angeles, CA · $7,956 in drug and device payments (2025) · Telehealth · (213) 977-1214
Dr. Lauren Midthun, MD, DDS
Los Angeles, CA · $1,536 in drug and device payments (2025) · Telehealth · (310) 231-2121
Dr. Lauren Pinter-brown, MD
Los Angeles, CA · $4,795 in drug and device payments (2025) · Telehealth · (310) 829-5471
Dr. Lawrence Piro, M.D.
Los Angeles, CA · No drug or device payments recorded (2025) · Telehealth · (310) 231-2121
Dr. Leonid Kleynberg, M.D.
Los Angeles, CA · $1,554 in drug and device payments (2025) · Telehealth · (323) 965-9995
Dr. Leo Orr, M.D.
Los Angeles, CA · $3,554 in drug and device payments (2025) · Telehealth · (213) 481-3948
Dr. Madeline Macdonald, MD
Los Angeles, CA · $99 in drug and device payments (2025) · (310) 794-4955
Dr. Mahshid Mosallaei-benjamin, M.D.
Los Angeles, CA · $31 in drug and device payments (2025) · Telehealth · (310) 825-5756
Dr. Maria Dungo, M.D.
Los Angeles, CA · $160 in drug and device payments (2025) · (310) 231-2121
Dr. Maria Velez Velez, M.D.
Los Angeles, CA · $8,044 in drug and device payments (2025) · Telehealth · (310) 794-4955
Dr. Marjorie Bernstein-singer, MD
Los Angeles, CA · No drug or device payments recorded (2025) · (323) 783-4011
Dr. Mark Forsberg, MD
Los Angeles, CA · $166 in drug and device payments (2025) · (800) 872-2273
Dr. Mary Ichiuji, MD
Los Angeles, CA · No drug or device payments recorded (2025) · (323) 857-2000
Dr. Mary Territo, MD
Los Angeles, CA · No drug or device payments recorded (2025) · (310) 206-6909
Dr. Matthew Rettig, MD
Los Angeles, CA · $51,111 in drug and device payments (2025) · Telehealth · (310) 794-7152
Dr. Maxwell Kroloff, M.D.
Los Angeles, CA · $85 in drug and device payments (2025) · Telehealth · (310) 825-7375
Dr. Michael Cho, MD
Los Angeles, CA · $865 in drug and device payments (2025) · Telehealth · (301) 514-7397
Dr. Michael Glowalla, MD
Los Angeles, CA · No drug or device payments recorded (2025) · (323) 783-4011
Dr. Michael Maranzano, M.D.
Los Angeles, CA · $1,375 in drug and device payments (2025) · (323) 409-7804
Dr. Michael Rosove, MD
Los Angeles, CA · No drug or device payments recorded (2025) · (310) 825-6301
Dr. Michael Snell, MD
Los Angeles, CA · $91 in drug and device payments (2025) · (562) 735-3226
Dr. Michael Van Scoy-mosher, M.D.
Los Angeles, CA · No drug or device payments recorded (2025) · (310) 659-9397
Dr. Mihee Park, M.D.
Los Angeles, CA · $24 in drug and device payments (2025) · (323) 226-7556
Dr. Monica Mead, M.D.
Los Angeles, CA · No drug or device payments recorded (2025) · (310) 825-5756
Dr. Namphuong Tran
Los Angeles, CA · $15 in drug and device payments (2025) · (310) 914-2905
Dr. Nancy Feldman, MD
Los Angeles, CA · No drug or device payments recorded (2025) · (310) 825-0631
Dr. Nara Lee, MD
Los Angeles, CA · $194 in drug and device payments (2025) · Telehealth · (323) 865-3105
Dr. Navid Hafez, M.D.
Los Angeles, CA · $2,115 in drug and device payments (2025) · Telehealth · (310) 231-2121
Dr. Neil Shah, MD
Los Angeles, CA · $112 in drug and device payments (2025) · Telehealth · (310) 825-6301
Dr. Nenad Antic, MC
Los Angeles, CA · $2,424 in drug and device payments (2025) · (213) 246-2422
Dr. Nicholas Mcandrew, M.D.
Los Angeles, CA · $9,622 in drug and device payments (2025) · Telehealth · (310) 205-0771
Dr. Patricia Ganz, MD
Los Angeles, CA · $3,813 in drug and device payments (2025) · (310) 206-1404
Dr. Patrick Chun, M.D.
Los Angeles, CA · No drug or device payments recorded (2025) · (310) 206-1214
Dr. Peter Kennedy, MD
Los Angeles, CA · No drug or device payments recorded (2025) · (213) 484-6474
Dr. Preet Chaudhary, M.D., PHD
Los Angeles, CA · $2,280 in drug and device payments (2025) · (323) 865-3105
Dr. Raghuveer Ranganathan, M.D.
Los Angeles, CA · $132,618 in drug and device payments (2025) · (323) 865-3950
Dr. Rahel Demisse, M.D.
Los Angeles, CA · $122 in drug and device payments (2025) · Telehealth · (323) 226-7556
Dr. Rahul Naik, M.D.
Los Angeles, CA · $45,529 in drug and device payments (2025) · Telehealth · (323) 264-0430
Dr. Rebecca Nayeri, M.D.
Los Angeles, CA · No drug or device payments recorded (2025) · (310) 478-3711
Dr. Richard Pietras, MD
Los Angeles, CA · No drug or device payments recorded (2025) · (310) 825-6301
Dr. Robert Hsu, M.D.
Los Angeles, CA · $54,929 in drug and device payments (2025) · Telehealth · (323) 865-3963
Dr. Robert Leibowitz, MD
Los Angeles, CA · No drug or device payments recorded (2025) · (310) 229-3555
Dr. Robert Vescio, M.D.
Los Angeles, CA · $137,552 in drug and device payments (2025) · Telehealth · (310) 423-1825
Dr. Roman Kleynberg, M.D.
Los Angeles, CA · $1,195 in drug and device payments (2025) · (323) 965-5679
Dr. Ronald Mitsuyasu, MD
Los Angeles, CA · No drug or device payments recorded (2025) · (310) 794-9718
Dr. Ronald Paquette, MD
Los Angeles, CA · $9,072 in drug and device payments (2025) · Telehealth · (310) 825-6301
Dr. Sameer Kulkarni, MD
Los Angeles, CA · No drug or device payments recorded (2025) · Telehealth · (323) 783-5722
Dr. Samuel Slomowitz, M.D.
Los Angeles, CA · No drug or device payments recorded (2025) · Telehealth · (805) 496-5153
Dr. Sanjai Sharma, MD
Los Angeles, CA · $344 in drug and device payments (2025) · (310) 368-3247
Dr. Sarah Larson, M.D.
Los Angeles, CA · $11,387 in drug and device payments (2025) · Telehealth · (310) 825-7768

Conditions Hematology & Oncology providers in California commonly treat

Patients often search by condition rather than specialty. These are conditions typically managed by Hematology & Oncology providers. Individual practices vary, so confirm with the provider before booking.

Common questions

How many Hematology & Oncology providers are in California?

There are 1,582 Hematology & Oncology providers with active NPI records practicing in California, according to federal NPPES data refreshed monthly.

Do Hematology & Oncology providers in California offer telehealth?

Yes. 855 of the 1,582 Hematology & Oncology providers in California (about 54%) report offering telehealth services in CMS data.

Which cities in California have the most Hematology & Oncology providers?

Los Angeles (152), San Diego (89), Sacramento (77) have the highest concentration of Hematology & Oncology providers in California.

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

995 of 1,582 Hematology & Oncology providers in California (63%) received at least one payment from a drug or device company in 2025, according to the federal Open Payments program.

What conditions do Hematology & Oncology providers in California treat?

Hematology & Oncology providers commonly treat breast cancer, lung cancer, lymphoma, leukemia, anemia 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 Hematologists and Oncologists in California work in independent practices or large health systems?

Among 1,081 Hematologists and Oncologists in California enrolled in Medicare, 11% bill through a solo or small practice with fewer than 10 clinicians, 12% through a mid-size group of 10 to 99, and 77% through a large group or health system with 100 or more clinicians, according to CMS enrollment records.

Which hospitals do Hematologists and Oncologists in California work at?

According to CMS facility affiliation records, the California hospitals where the most Hematologists and Oncologists hold privileges are Ronald Reagan UCLA Medical Center in Los Angeles; Uci Health-Orange in Orange; Santa Monica - UCLA Med Ctr & Orthopaedic Hospital in Santa Monica.

Related reading on HealthcareDiscovery.AI

Hematology & Oncology in all 50 states Search all 1,582 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 Hematology & Oncology in California? Get featured.