Ruth Williamson, MD

Individual provider Radiation Oncology Physician · NPI 1952486912

Ruth Williamson, MD practises Radiation Oncology in Pasadena, California. Graduated from University of Southern California Keck School of Medicine in 1989, 37 years ago. Practices with Cedars-Sinai Medical Care Foundation, a 1,696-clinician group, works from 2 locations and accepts Medicare assignment. Licensed in California.

Years since qualifying: 37
Trained at: University of Southern California Keck School of Medicine
Licensed in: CA
In the registry since: 2006

What do these letters mean?

MD — Doctor of Medicine: A physician who completed allopathic medical school.

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Practice location Address checks out

625 S Fair Oaks Ave Ste 100
Pasadena, CA 91105-2640
Phone: (626) 397-5149
Fax: (310) 397-2147

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

Additional practice locations (1)

100 W California Blvd, Pasadena, CA 91105-3010 — (626) 397-5149

Specialties & licences

Radiation Oncology Physician (primary)	Taxonomy 2085R0001X · Licence G707B5C (CA)

Record details

NPI number	1952486912
Entity type	Individual (Type 1)
Gender	Female
Credentials	MD
Sole proprietor	No
NPI enumerated	October 26, 2006
Last updated in NPPES	October 13, 2022
Certification date	October 13, 2022

Medicare enrollment

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

Medicare specialty	RADIATION ONCOLOGY
Medical school	UNIVERSITY OF SOUTHERN CALIFORNIA KECK SCHOOL OF MEDICINE
Graduated	1989 (37 years in practice)
Group practice	Cedars-Sinai Medical Care Foundation — 1696 clinicians
Accepts Medicare assignment	Yes — accepts the Medicare-approved amount

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients	146
Services billed	1,550 a service is one billed item, such as a visit, a test or a procedure
Average patient age	75

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

Usc Verdugo Hills Hospital Hospital · Glendale, CA
Huntington Hospital Hospital · Pasadena, CA

Also affiliated with 1 hospital, which CMS identifies by certification number only.

Colleagues at Cedars-Sinai Medical Care Foundation

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 1696 clinicians in the practice; 12 are shown here.

Leah Francesca Breen, MD Student in an Organized Health Care Education/Training Program · Beverly Hills, CA
Ava Y Feng, MD Hospitalist Physician · West Hollywood, CA
Dr. Avner G. Gereboff, MD Anesthesiology Physician · West Hollywood, CA
Mr. Shahram Hadidchi, MD Diagnostic Radiology Physician · Los Angeles, CA
Lacy Little Knowles, DO Adult Medicine Physician · Los Angeles, CA
Daniel Manzoor, MD Anatomic Pathology & Clinical Pathology Physician · Los Angeles, CA
Dr. Bahar Abiri Mjos, DO Anesthesiology Physician · West Hollywood, CA
Lisa Ugoma Obasi, MD Obstetrics & Gynecology Physician · Los Angeles, CA
Brandon Say Student in an Organized Health Care Education/Training Program · Stanford, CA
Ahmed M. Shalabi, MD Anesthesiology Physician · West Hollywood, CA
Dr. Stephen Tang, MD Internal Medicine Physician · Santa Monica, CA
Dr. Arthur W. Wu, MD Otolaryngology Physician · Los Angeles, CA