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

Dr. Joan Joonsun Ryoo, MD, MSHS

Individual provider Surgery Physician · NPI 1699854596

Dr. Joan Joonsun Ryoo, MD, MSHS practises Radiation Oncology in Los Angeles, California. Graduated from Harvard Medical School in 2004, 22 years ago. Practices with Southern California Permanente Medical Group, an 11,242-clinician group, accepts Medicare assignment and offers telehealth. Licensed in California and Massachusetts.

Years since qualifying
22
Trained at
Harvard Medical School
Licensed in
CA, MA
In the registry since
2006
Specialties on file
2
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

4950 W Sunset Blvd Second Fl
Los Angeles, CA 90027-5822
Phone: (323) 783-2841
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Therapeutic Radiology Physician (primary) Taxonomy 2085R0203X · Licence A98329 (CA)
Surgery Physician Taxonomy 208600000X · Licence 221442 (MA)

Record details

NPI number1699854596
Entity typeIndividual (Type 1)
GenderFemale
Credentials MD , MSHS
Sole proprietorNo
NPI enumeratedNovember 3, 2006
Last updated in NPPESDecember 1, 2021

Medicare enrollment

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

Medicare specialtyRADIATION ONCOLOGY
Medical schoolHARVARD MEDICAL SCHOOL
Graduated 2004 (22 years in practice)
Group practice Southern California Permanente Medical Group — 11242 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations4 on file with Medicare

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 patients20
Services billed 77 a service is one billed item, such as a visit, a test or a procedure
Average patient age69

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.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $218 2 payments · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Colleagues at Southern California Permanente Medical Group

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 11242 clinicians in the practice; 12 are shown here.

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