Dr. Ethan-Quan H Nguyen, MD practises Dermatology in Riverside, California. Graduated from Georgetown University School of Medicine in 1991, 35 years ago. Accepts Medicare assignment. Licensed in California.
From the CMS Doctors & Clinicians file — this clinician is
enrolled in Medicare.
Medicare specialty
DERMATOLOGY
Medical school
GEORGETOWN UNIVERSITY SCHOOL OF MEDICINE
Graduated
1991 (35 years in practice)
Accepts Medicare assignment
Yes — accepts the Medicare-approved amount
Procedures
From CMS Care Compare, which counts the procedures a clinician billed to
Original Medicare and Medicare Advantage over a recent 12-month period.
CMS reports a fixed list of common procedures, so this is not everything
the clinician does. Counts of 10 or fewer are given as a range, because
CMS withholds small numbers.
Melanoma (skin cancer) excision
92 times · 92nd percentile
Removal of skin lesions
372 times · 84th percentile
Skin biopsy
161 times · 82nd percentile
Removal of skin cancer
179 times · 32nd percentile
Removal of nail tissue
1–10 times
Removal of tissue
1–10 times
Removal or shaving of skin growth
1–10 times
The percentile compares how often this clinician performed the procedure
with other clinicians who performed it, as CMS calculates it. It measures
volume, not outcomes or skill.
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
394
Services billed
2,728
a service is one billed item, such as a visit, a test or a procedure
Average patient age
77
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
$2,157 96 payments · a meal or drink at a meeting or visit, not a fee
Education
$194 3 payments · educational material or training, 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.