Quick answers
- Where does John Marcelis see patients?
- Medicare's clinician data lists 2 practice locations, including Glen Mills, PA and Warminster, PA. Call before your visit to confirm the address.
- What is John Marcelis's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does John Marcelis accept Medicare assignment?
- Yes. Medicare's clinician data says John Marcelis 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 Marcelis?
- (610) 387-4520, as listed in official Medicare / NPI Registry data.
- What is John Marcelis's NPI number?
- 1285667105. 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 John Marcelis is enrolled with Medicare (CMS data updated 2026-10-02).
- 100 Maris Grove WayGlen Mills, PA 19342 (610) 387‑4520
- 10000 Ann'S Choice WayWarminster, PA 18974 (215) 443‑3850
Group practices
Medicare enrollment lists John Marcelis as a member of this group (CMS data updated 2026-10-02).
- Erickson Health Medical Group of Pennsylvania PC20 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Glen Mills
Clinicians with the same Medicare primary specialty in Glen Mills, PA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Temple University School Of Medicine |
| Graduation year | 1987 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1285667105 |
| 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