Quick answers
- Does Irene Y. Tong accept Medicare assignment?
- Yes. Medicare's clinician data says Irene Y. Tong 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 Y. Tong see?
- In 2024, CMS data shows 292 Original Medicare patients and 49,576 services for Irene Y. Tong. This counts Original Medicare only and measures volume, not quality.
- What is Irene Y. Tong's NPI number?
- 1962439299. 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 Y. Tong, 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 | 292 |
|---|---|
| Services billed to Medicare | 49,576 |
| Different services or procedures | 31 |
| Participating Medicare provider | Yes |
| Average age of these patients | 75 |
Most frequent services
- Injection, romosozumab-aqqg, 1 mg (J3111)12,392 services
- Injection, denosumab, 1 mg (J0897)4,020 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)764 services
- Injection of drug or substance under skin or into muscle (96372)128 services
- Administration of non-hormonal anti-neoplastic chemotherapy under skin or into muscle (96401)114 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%
- Arthritis75%
- High blood pressure71%
- Osteoporosis39%
- Diabetes28%
- Chronic kidney disease26%
Practice locations
Addresses where Irene Y. Tong is enrolled with Medicare (CMS data updated October 2, 2026).
- 23206 Lyons Ave, Suite 106Santa Clarita, CA 91321 (661) 505‑9901
- 301 S Fair Oaks AvePasadena, CA 91105 (626) 296‑2910
Group practices
Medicare enrollment lists Irene Y. Tong as a member of this group (CMS data updated October 2, 2026).
- American Arthritis and Rheumatology Associates-Ca PC14 clinicians in the group
Specialties
- Rheumatologyprimary
Other rheumatologists in Santa Clarita
Clinicians with the same Medicare primary specialty in Santa Clarita, CA — not a recommendation.
Other clinicians in American Arthritis and Rheumatology Associates-Ca PC
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Southern California Keck School Of Medicine |
| Graduation year | 1976 (50 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1962439299 |
| 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
- 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