Quick answers
- Which hospitals does Rene A. Castillo work at?
- Medicare's official clinician data lists Rene A. Castillo at 4 hospitals: CHRISTUS Santa Rosa Hospital-San Marcos, Guadalupe Regional Medical Center, Memorial Hospital and St David's South Austin Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Rene A. Castillo see patients?
- Medicare's clinician data lists 2 practice locations, including San Marcos, TX and Austin, TX. Call before your visit to confirm the address.
- What is Rene A. Castillo's specialty?
- Medicare lists Medical Oncology as the primary specialty.
- Does Rene A. Castillo accept Medicare assignment?
- Yes. Medicare's clinician data says Rene A. Castillo 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 Rene A. Castillo offer telehealth?
- Medicare's clinician data says Rene A. Castillo offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Rene A. Castillo?
- (512) 396-5199, as listed in official Medicare / NPI Registry data.
- What is Rene A. Castillo's NPI number?
- 1134186166. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Rene A. Castillo works
Medicare's Facility Affiliation Data lists Rene A. Castillo at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- CHRISTUS Santa Rosa Hospital-San MarcosSan Marcos, TX · Acute Care Hospital · CCN 450272
- Guadalupe Regional Medical CenterSeguin, TX · Acute Care Hospital · CCN 450104
- Memorial HospitalGonzales, TX · Acute Care Hospital · CCN 450235
- St David's South Austin Medical CenterAustin, TX · Acute Care Hospital · CCN 450713
Practice locations
Addresses where Rene A. Castillo is enrolled with Medicare (CMS data updated 2026-10-02).
- 1308 Wonder World DrSan Marcos, TX 78666 (512) 396‑5199
- 4101 James Casey St, Suite 100Austin, TX 78745 (512) 447‑2202
Group practices
Medicare enrollment lists Rene A. Castillo as a member of this group (CMS data updated 2026-10-02).
- Texas Oncology PA1,014 clinicians in the group
Specialties
- Medical Oncologyprimary
Other oncologists in Texas
Clinicians with the same Medicare primary specialty in Texas — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1987 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1134186166 |
| 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