Eric Changchien, MD

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.

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.

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.

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.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

• Kaiser Foundation Hospital - Orange County - Anaheim Hospital · Anaheim, CA

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.

• Dr. Maria Isabel Abundis-Barrera, MD Family Medicine Physician · Santa Clarita, CA
• Tik Lung Dion Fung, MD Neurology Physician · Lancaster, CA
• Mrs. Laura Dawn Harman Registered Nurse · Westlake Village, CA
• Dr. Sai-Hung Hui, MD Emergency Medicine Physician · Sylmar, CA
• Dr. Shahid Javed, MD Student in an Organized Health Care Education/Training Program · Woodland Hills, CA
• Dr. Jeffrey Gerald Karst, MD Diagnostic Radiology Physician · Loma Linda, CA
• Dr. Aldon Li, MD Internal Medicine Physician · West Hollywood, CA
• Khoalinh Thieu Luong, MD Obstetrics & Gynecology Physician · San Jose, CA
• MS. Vanessa Sun, MD Obstetrics & Gynecology Physician · Los Angeles, CA
• Dr. Marco James Tomassi, MD Surgery Physician · Los Angeles, CA
• Michelle Tomassi, MD Emergency Medicine Physician · Downey, CA
• Jonathan Wu, MD Urology Physician · Anaheim, CA