Quick answers
- Which hospitals does John J. Maciejewski work at?
- Medicare's official clinician data lists John J. Maciejewski at 1 hospital: University of Michigan Health System. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does John J. Maciejewski see patients?
- Medicare's clinician data lists 12 practice locations, including Ann Arbor, MI. Call before your visit to confirm the address.
- What is John J. Maciejewski's specialty?
- Medicare lists Hematology as the primary specialty, and also Hematology/Oncology and Internal Medicine.
- Does John J. Maciejewski accept Medicare assignment?
- Yes. Medicare's clinician data says John J. Maciejewski 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.
- Does John J. Maciejewski offer telehealth?
- Medicare's clinician data says John J. Maciejewski offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for John J. Maciejewski?
- (734) 936-5738, as listed in official Medicare / NPI Registry data.
- What is John J. Maciejewski's NPI number?
- 1235334137. 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. Maciejewski works
Medicare's Facility Affiliation Data lists John J. Maciejewski at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- University of Michigan Health SystemAnn Arbor, MI · Acute Care Hospital · CCN 230046
Practice locations
Addresses where John J. Maciejewski is enrolled with Medicare (CMS data updated 2026-10-02). The first 5 of 12; the Medicare profile lists all.
- 1500 E Medical Ctr, Suite 0331Ann Arbor, MI 48109 (734) 936‑5738
- 1500 E Medical Ctr 2nd Floor Rec, Taubman CenterAnn Arbor, MI 48109 (734) 936‑5020
- 1500 E Medical Ctr DrAnn Arbor, MI 48109
- 1500 E Medical Ctr Dr 1st Fl, Taubman Ctr Rec DAnn Arbor, MI 48109 (734) 936‑4185
- 1500 E Medical Ctr Dr 1st Fl Rec D, Taubman CenterAnn Arbor, MI 48109 (734) 764‑5175
Group practices
Medicare enrollment lists John J. Maciejewski as a member of this group (CMS data updated 2026-10-02).
- Regents of the University of Michigan3,346 clinicians in the group
Specialties
- Hematologyprimary
- Hematology/Oncologyalso
- Internal Medicinealso
Other hematologists in Ann Arbor
Clinicians with the same Medicare primary specialty in Ann Arbor, MI — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | R Franklin University Of Med & Sci/chicago Medical School |
| Graduation year | 2001 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1235334137 |
| 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