Jeffrey Ahn, MD

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.

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.

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.

• Uci Health-Orange Hospital · Orange, CA

Colleagues at Uc Regents

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 306 clinicians in the practice; 12 are shown here.

• Yongen Chang, MD, PHD Specialist · Orange, CA
• Angela Goffredo Fleischman, MD Medical Oncology Physician · Orange, CA
• Mrs. Christina Marie Kirk, NP Nurse Practitioner · Orange, CA
• Dr. Shaista Malik, MD Cardiovascular Disease Physician · Orange, CA
• Dr. Nataliya Mar, MD Student in an Organized Health Care Education/Training Program · Orange, CA
• Lawrence Nguyen, DO Nephrology Physician · Orange, CA
• Dr. Zahra Pakbaz, MD Hematology (Internal Medicine) Physician · Orange, CA
• Dr. Carlos Saad, MD Gastroenterology Physician · Santa Ana, CA
• Sherry Finn Schulman, RDN Registered Dietitian · San Juan Capistrano, CA
• Eugene Thang Van, DO Internal Medicine Physician · Long Beach, CA
• Mohammadbagher Ziari, MD Hematology & Oncology Physician · Corona, CA
• Anne Zuzelski, MD Physical Medicine & Rehabilitation Physician · San Juan Capistrano, CA

Other providers in Orange

• Zhaohui Liao Arter, MD

  Individual Hematology & Oncology Physician · NPI 1184116451

  101 The City Dr S, Orange, CA 92868-3201 · (714) 456-5670

• Polina Bellman, MD

  Individual Hematology & Oncology Physician · NPI 1306349196

  101 The City Dr S, Orange, CA 92868-3201 · (714) 456-5153

• Timothy Euiwon Byun, MD

  Individual Hematology & Oncology Physician · NPI 1871545012

  805 W La Veta Ave Ste 101, Orange, CA 92868-3928 · (714) 835-1800

• Center for Cancer and Blood Disorders

  Organization Hematology & Oncology Physician · NPI 1083132625

  363 S Main St Ste 485, Orange, CA 92868-3833 · (714) 835-4800