Quick answers
- Which hospitals does Gregory Wallis work at?
- Medicare's official clinician data lists Gregory Wallis at 3 hospitals: Lake Chelan Community Hospital, Parker Indian Health Center and Pullman Regional Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Gregory Wallis see patients?
- Medicare's clinician data lists 1 practice location in Parker, AZ. Call before your visit to confirm the address.
- What is Gregory Wallis's specialty?
- Medicare lists Emergency Medicine as the primary specialty.
- Does Gregory Wallis accept Medicare assignment?
- Yes. Medicare's clinician data says Gregory Wallis 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 Gregory Wallis?
- (928) 669-2137, as listed in official Medicare / NPI Registry data.
- What is Gregory Wallis's NPI number?
- 1790308278. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Gregory Wallis works
Medicare's Facility Affiliation Data lists Gregory Wallis at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Lake Chelan Community HospitalChelan, WA · Critical Access Hospital · CCN 501334
- Parker Indian Health CenterParker, AZ · Critical Access Hospital · CCN 031307
- Pullman Regional HospitalPullman, WA · Critical Access Hospital · CCN 501331
Practice locations
Addresses where Gregory Wallis is enrolled with Medicare (CMS data updated 2026-10-02).
- 12033 Agency RdParker, AZ 85344 (928) 669‑2137
Group practices
Medicare enrollment lists Gregory Wallis as a member of this group (CMS data updated 2026-10-02).
- DHHS IHS Phoenix Area59 clinicians in the group
Specialties
- Emergency Medicineprimary
Other emergency medicine doctors in Parker
Clinicians with the same Medicare primary specialty in Parker, AZ — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Graduation year | 2020 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1790308278 |
| 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