Quick answers
- Which hospitals does Sean S. To work at?
- Medicare's official clinician data lists Sean S. To at 3 hospitals: Casa Colina Hospital, Pomona Valley Hospital Medical Center and San Antonio Regional Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Sean S. To see patients?
- Medicare's clinician data lists 2 practice locations, including Chino, CA and Rancho Cucamonga, CA. Call before your visit to confirm the address.
- What is Sean S. To's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Sean S. To accept Medicare assignment?
- Yes. Medicare's clinician data says Sean S. To 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 Sean S. To offer telehealth?
- Medicare's clinician data says Sean S. To offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Sean S. To?
- (909) 988-1000, as listed in official Medicare / NPI Registry data.
- What is Sean S. To's NPI number?
- 1922163310. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Sean S. To works
Medicare's Facility Affiliation Data lists Sean S. To at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Casa Colina HospitalPomona, CA · Acute Care Hospital · CCN 050782
- Pomona Valley Hospital Medical CenterPomona, CA · Acute Care Hospital · CCN 050231
- San Antonio Regional HospitalUpland, CA · Acute Care Hospital · CCN 050099
Practice locations
Addresses where Sean S. To is enrolled with Medicare (CMS data updated 2026-10-02).
- 5562 Philadelphia St, Suite 201Chino, CA 91710 (909) 988‑1000
- 8283 Grove Ave, Suite 201Rancho Cucamonga, CA 91730 (909) 981‑6644
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Chino
Clinicians with the same Medicare primary specialty in Chino, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | R Franklin University Of Med & Sci/chicago Medical School |
| Graduation year | 1998 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1922163310 |
| 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