Quick answers
- Which hospitals does John R. Tretter work at?
- Medicare's official clinician data lists John R. Tretter at 1 hospital: Banner Casa Grande Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does John R. Tretter see patients?
- Medicare's clinician data lists 2 practice locations, including Phoenix, AZ and Casa Grande, AZ. Call before your visit to confirm the address.
- What is John R. Tretter's specialty?
- Medicare lists Cardiovascular Disease (Cardiology) as the primary specialty, and also Internal Medicine.
- Does John R. Tretter accept Medicare assignment?
- Yes. Medicare's clinician data says John R. Tretter 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 John R. Tretter?
- (480) 501-9475, as listed in official Medicare / NPI Registry data.
- What is John R. Tretter's NPI number?
- 1346234564. 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 R. Tretter works
Medicare's Facility Affiliation Data lists John R. Tretter at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Banner Casa Grande Medical CenterCasa Grande, AZ · Acute Care Hospital · CCN 030016
Practice locations
Addresses where John R. Tretter is enrolled with Medicare (CMS data updated 2026-10-02).
- 1327 E Chandler Blvd, Suite 106Phoenix, AZ 85048 (480) 501‑9475
- 803 N Salk DrCasa Grande, AZ 85122 (520) 836‑6682
Group practices
Medicare enrollment lists John R. Tretter as a member of these groups (CMS data updated 2026-10-02).
- Premier Cardiovascular Center, PLC6 clinicians in the group
- Stone Med LLC2 clinicians in the group
Specialties
Find other Cardiovascular Disease (Cardiology) doctors in Arizona →
Other cardiologists in Phoenix
Clinicians with the same Medicare primary specialty in Phoenix, AZ — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1985 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1346234564 |
| 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