Quick answers
- Where does Marcellus Walker see patients?
- Medicare's clinician data lists 2 practice locations, including New York, NY and Astoria, NY. Call before your visit to confirm the address.
- What is Marcellus Walker's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Marcellus Walker accept Medicare assignment?
- Yes. Medicare's clinician data says Marcellus Walker 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 Marcellus Walker?
- (646) 518-0163, as listed in official Medicare / NPI Registry data.
- What is Marcellus Walker's NPI number?
- 1003038274. 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 Marcellus Walker is enrolled with Medicare (CMS data updated 2026-10-02).
- 212 E 23rd StNew York, NY 10010 (646) 518‑0163
- 2248 31st StAstoria, NY 11105 (718) 571‑9192
Group practices
Medicare enrollment lists Marcellus Walker as a member of this group (CMS data updated 2026-10-02).
- City Medical of Upper East Side PLLC658 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in New York
Clinicians with the same Medicare primary specialty in New York, NY — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Loyola University Of Chicago, Stritch School Of Medicine |
| Graduation year | 1978 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1003038274 |
| 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