Quick answers
- Which hospitals does Keith D. Marcus work at?
- Medicare's official clinician data lists Keith D. Marcus at 1 hospital: Corewell Health Ludington Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Keith D. Marcus see patients?
- Medicare's clinician data lists 3 practice locations, including Fremont, MI, Kentwood, MI and Ludington, MI. Call before your visit to confirm the address.
- What is Keith D. Marcus's specialty?
- Medicare lists Hospitalist as the primary specialty, and also Internal Medicine.
- Does Keith D. Marcus accept Medicare assignment?
- Yes. Medicare's clinician data says Keith D. Marcus 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 Keith D. Marcus?
- (616) 391-3139, as listed in official Medicare / NPI Registry data.
- What is Keith D. Marcus's NPI number?
- 1255371365. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Keith D. Marcus works
Medicare's Facility Affiliation Data lists Keith D. Marcus at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Corewell Health Ludington HospitalLudington, MI · Acute Care Hospital · CCN 230110
Practice locations
Addresses where Keith D. Marcus is enrolled with Medicare (CMS data updated 2026-10-02).
- 212 S Sullivan Ave, Corewell Health Medical Group WestFremont, MI 49412 (616) 391‑3139
- 4444 Kalamazoo Ave SE, 200 Corewell Health Medical Group WestKentwood, MI 49508 (616) 391‑5600
- 5 Atkinson Dr, 302 Corewell Health Medical Group WestLudington, MI 49431 (616) 267‑8700
Group practices
Medicare enrollment lists Keith D. Marcus as a member of this group (CMS data updated 2026-10-02).
- Spectrum Health Primary Care Partners2,294 clinicians in the group
Specialties
- Hospitalistprimary
- Internal Medicinealso
Other hospitalists in Michigan
Clinicians with the same Medicare primary specialty in Michigan — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Iowa, Rj & L Carver College Of Medicine |
| Graduation year | 1985 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1255371365 |
| 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