Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

John Joseph Maciejewski, MD

Individual provider Internal Medicine Physician · NPI 1235334137

John Joseph Maciejewski, MD is a Hematology in Ann Arbor, Michigan. Graduated from R Franklin University of Med & SCI/Chicago Medical School in 2001, 25 years ago. Practices with Regents of the University of Michigan, a 3,271-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Illinois and Michigan.

Years since qualifying
25
Trained at
R Franklin University of Med & SCI/Chicago Medical School
Licensed in
IL, MI
In the registry since
2007
Specialties on file
4
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

1500 E Medical Center Dr
Ann Arbor, MI 48109-5000
Phone: (734) 936-4000
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Hematology (Internal Medicine) Physician (primary) Taxonomy 207RH0000X · Licence 4301116418 (MI)
Internal Medicine Physician Taxonomy 207R00000X · Licence 4301116418 (MI)
Hematology (Internal Medicine) Physician Taxonomy 207RH0000X · Licence 036-109957 (IL)
Hematology & Oncology Physician Taxonomy 207RH0003X · Licence 036-109957 (IL)

Record details

NPI number1235334137
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJune 19, 2007
Last updated in NPPESFebruary 19, 2020
Certification dateFebruary 19, 2020
Mailing address3621 S State St, Ann Arbor, MI 48108-1633

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyHEMATOLOGY
Also practisesHEMATOLOGY/ONCOLOGY, INTERNAL MEDICINE
Medical schoolR FRANKLIN UNIVERSITY OF MED & SCI/CHICAGO MEDICAL SCHOOL
Graduated 2001 (25 years in practice)
Group practice Regents Of The University Of Michigan — 3271 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations13 on file with Medicare

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