Quick answers
- Which hospitals does William Matsui work at?
- Medicare's official clinician data lists William Matsui at 1 hospital: Ascension Seton Medical Center Austin. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does William Matsui see patients?
- Medicare's clinician data lists 5 practice locations, including Austin, TX and Houston, TX. Call before your visit to confirm the address.
- What is William Matsui's specialty?
- Medicare lists Medical Oncology as the primary specialty.
- Does William Matsui accept Medicare assignment?
- Yes. Medicare's clinician data says William Matsui accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- Does William Matsui offer telehealth?
- Medicare's clinician data says William Matsui offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for William Matsui?
- (512) 324-7300, as listed in official Medicare / NPI Registry data.
- What is William Matsui's NPI number?
- 1568411049. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where William Matsui works
Medicare's Facility Affiliation Data lists William Matsui at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Ascension Seton Medical Center AustinAustin, TX · Acute Care Hospital · CCN 450056
Practice locations
Addresses where William Matsui is enrolled with Medicare (CMS data updated 2026-10-02).
- 1400 N Ih 35Austin, TX 78701
- 1400 N Ih 35 Ll, Cl400 Tri County Prac AssocAustin, TX 78701 (512) 324‑7300
- 1515 Holcombe BlvdHouston, TX 77030 (713) 792‑6313
- 1601 Trinity StAustin, TX 78712 (833) 882‑2737
- 1601 Trinity St, Stop 804Austin, TX 78712 (512) 324‑7865
Group practices
Medicare enrollment lists William Matsui as a member of these groups (CMS data updated 2026-10-02).
- Physicians Referral Service2,765 clinicians in the group
- Seton Family of Doctors792 clinicians in the group
- The University of Texas at Austin153 clinicians in the group
Specialties
- Medical Oncologyprimary
Other oncologists in Austin
Clinicians with the same Medicare primary specialty in Austin, TX — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of California, San Francisco School Of Medicine |
| Graduation year | 1995 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1568411049 |
| 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 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- 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