Quick answers
- Does Irene S. Tsai accept Medicare assignment?
- Yes. Medicare's clinician data says Irene S. Tsai accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Irene S. Tsai see?
- In 2024, CMS data shows 878 Original Medicare patients and 2,343 services for Irene S. Tsai. This counts Original Medicare only and measures volume, not quality.
- What is Irene S. Tsai's NPI number?
- 1447558044. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Irene S. Tsai, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 878 |
|---|---|
| Services billed to Medicare | 2,343 |
| Different services or procedures | 23 |
| Participating Medicare provider | Yes |
| Average age of these patients | 72 |
Most frequent services
- Screening 3d breast mammography (77063)529 services
- Screening mammography (77067)529 services
- Injection, gadobutrol, 0.1 ml (A9585)515 services
- Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066) (G0279)138 services
- Complete ultrasound scan of 1 breast (76641)132 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High cholesterol75%
- High blood pressure60%
- Arthritis53%
- Osteoporosis42%
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)31%
- Diabetes23%
Hospitals where Irene S. Tsai works
Medicare's Facility Affiliation Data lists Irene S. Tsai at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- UCI Health-OrangeOrange, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050348
Practice locations
Addresses where Irene S. Tsai is enrolled with Medicare (CMS data updated October 2, 2026).
- 101 the City Dr SOrange, CA 92868 (714) 456‑7004
Group practices
Medicare enrollment lists Irene S. Tsai as a member of this group (CMS data updated October 2, 2026).
- UC Regents108 clinicians in the group
Specialties
- Diagnostic Radiologyprimary
Other radiologists in Orange
Clinicians with the same Medicare primary specialty in Orange, CA — not a recommendation.
Other clinicians in UC Regents
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2015 (11 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1447558044 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians