Quick answers
- Which hospitals does John A. Martin work at?
- Medicare's official clinician data lists John A. Martin at 2 hospitals: Mayo Clinic Hospital Rochester and UCI Health-Orange. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does John A. Martin see patients?
- Medicare's clinician data lists 4 practice locations, including Orange, CA and Rochester, MN. Call before your visit to confirm the address.
- What is John A. Martin's specialty?
- Medicare lists Gastroenterology as the primary specialty, and also Internal Medicine.
- Does John A. Martin accept Medicare assignment?
- Yes. Medicare's clinician data says John A. Martin 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 John A. Martin offer telehealth?
- Medicare's clinician data says John A. Martin offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for John A. Martin?
- (714) 456-7002, as listed in official Medicare / NPI Registry data.
- What is John A. Martin's NPI number?
- 1609808534. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where John A. Martin works
Medicare's Facility Affiliation Data lists John A. Martin at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Mayo Clinic Hospital RochesterRochester, MN · Acute Care Hospital · CCN 240010
- UCI Health-OrangeOrange, CA · Acute Care Hospital · CCN 050348
Practice locations
Addresses where John A. Martin is enrolled with Medicare (CMS data updated 2026-10-02).
- 101 the City Dr SOrange, CA 92868 (714) 456‑7002
- 1216 2nd St SWRochester, MN 55902 (507) 255‑5123
- 200 1st St SWRochester, MN 55905
- 201 W Ctr StRochester, MN 55902 (507) 255‑5123
Group practices
Medicare enrollment lists John A. Martin as a member of these groups (CMS data updated 2026-10-02).
- Mayo Clinic4,956 clinicians in the group
- UC Regents319 clinicians in the group
Specialties
- Gastroenterologyprimary
- Internal Medicinealso
Other gastroenterologists in Orange
Clinicians with the same Medicare primary specialty in Orange, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Virginia School Of Medicine |
| Graduation year | 1989 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1609808534 |
| 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