Quick answers
- Does Dien T. Ton-That accept Medicare assignment?
- Yes. Medicare's clinician data says Dien T. Ton-That 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.
- What is Dien T. Ton-That's NPI number?
- 1306074687. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Dien T. Ton-That works
Medicare's Facility Affiliation Data lists Dien T. Ton-That 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.
- Kaiser Foundation Hospital Fontana/OntarioFontana, CA · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 050140
Practice locations
Addresses where Dien T. Ton-That is enrolled with Medicare (CMS data updated October 2, 2026).
- 2295 S Vineyard AveOntario, CA 91761 (909) 724‑5000
- 9961 Sierra AveFontana, CA 92335 (909) 427‑5000
Group practices
Medicare enrollment lists Dien T. Ton-That as a member of this group (CMS data updated October 2, 2026).
- Southern California Permanente Medical Group11,293 clinicians in the group
Specialties
- Internal Medicineprimary
- Hospitalistalso
Other internal medicine doctors in Ontario
Clinicians with the same Medicare primary specialty in Ontario, CA — not a recommendation.
Other clinicians in Southern California Permanente Medical Group
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | Rutgers School Of Dental Medicine |
| Graduation year | 2009 (17 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1306074687 |
| 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
- 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