Quick answers
- Where does Thomas C. O Neil see patients?
- Medicare's clinician data lists 1 practice location in Tracy, CA. Call before your visit to confirm the address.
- What is Thomas C. O Neil's specialty?
- Medicare lists Ophthalmology as the primary specialty.
- Does Thomas C. O Neil accept Medicare assignment?
- Yes. Medicare's clinician data says Thomas C. O Neil 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.
- What is the phone number for Thomas C. O Neil?
- (209) 836-1155, as listed in official Medicare / NPI Registry data.
- What is Thomas C. O Neil's NPI number?
- 1831162999. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Practice locations
Addresses where Thomas C. O Neil is enrolled with Medicare (CMS data updated 2026-10-02).
- 303 W Eaton AveTracy, CA 95376 (209) 836‑1155
Specialties
- Ophthalmologyprimary
Other ophthalmologists in California
Clinicians with the same Medicare primary specialty in California — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Iowa, Rj & L Carver College Of Medicine |
| Graduation year | 1978 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1831162999 |
| 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 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