Quick answers
- Which hospitals does John J. Messmer Iii work at?
- Medicare's official clinician data lists John J. Messmer Iii at 3 hospitals: Milton S Hershey Medical Center, UPMC Pinnacle Hospitals and WellSpan Good Samaritan Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does John J. Messmer Iii see patients?
- Medicare's clinician data lists 1 practice location in Palmyra, PA. Call before your visit to confirm the address.
- What is John J. Messmer Iii's specialty?
- Medicare lists Family Practice as the primary specialty.
- Does John J. Messmer Iii accept Medicare assignment?
- Yes. Medicare's clinician data says John J. Messmer Iii 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 J. Messmer Iii?
- (717) 838-6305, as listed in official Medicare / NPI Registry data.
- What is John J. Messmer Iii's NPI number?
- 1669437414. 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 J. Messmer Iii works
Medicare's Facility Affiliation Data lists John J. Messmer Iii at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Milton S Hershey Medical CenterHershey, PA · Acute Care Hospital · CCN 390256
- UPMC Pinnacle HospitalsHarrisburg, PA · Acute Care Hospital · CCN 390067
- WellSpan Good Samaritan HospitalLebanon, PA · Acute Care Hospital · CCN 390066
Practice locations
Addresses where John J. Messmer Iii is enrolled with Medicare (CMS data updated 2026-10-02).
- 941 Park DrPalmyra, PA 17078 (717) 838‑6305
Group practices
Medicare enrollment lists John J. Messmer Iii as a member of this group (CMS data updated 2026-10-02).
- The Milton S Hershey Medical Center Physicians Group1,623 clinicians in the group
Specialties
- Family Practiceprimary
Other family doctors in Palmyra
Clinicians with the same Medicare primary specialty in Palmyra, PA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Pennsylvania State University College Of Medicine |
| Graduation year | 1977 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1669437414 |
| 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