Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Dr. Sean S. Szeja, MD

Individual provider Radiation Oncology Physician · NPI 1023351822

Dr. Sean S. Szeja, MD is a Radiation Oncology in Upland, California. Graduated from University of Arizona College of Medicine in 2013, 13 years ago. Practices with City of Hope Medical Foundation, a 959-clinician group, works from 2 locations, accepts Medicare assignment and offers telehealth. Licensed in California and Texas.

Years since qualifying
13
Trained at
University of Arizona College of Medicine
Licensed in
CA, TX
In the registry since
2013
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Practice location Address checks out

1100 San Bernardino Rd Ste 1100
Upland, CA 91786
Phone: (909) 949-2242
Fax: (909) 981-5783
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 7777 Milliken Ave Ste 110, Rancho Cucamonga, CA 91730 — (909) 949-2242

Specialties & licences

Radiation Oncology Physician (primary) Taxonomy 2085R0001X · Licence A152661 (CA)
Radiation Oncology Physician Taxonomy 2085R0001X · Licence BP10049243 (TX)

Record details

NPI number1023351822
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedMarch 29, 2013
Last updated in NPPESNovember 13, 2020
Certification dateNovember 13, 2020

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyRADIATION ONCOLOGY
Medical schoolUNIVERSITY OF ARIZONA COLLEGE OF MEDICINE
Graduated 2013 (13 years in practice)
Group practice City Of Hope Medical Foundation — 959 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations2 on file with Medicare

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