John Joseph Maciejewski, M.D.

NPI 1235334137ActiveIndividual· Internal Medicine, Hematology· Ann Arbor, MI

Internal Medicine, Hematology (M.D.) in Ann Arbor, Michigan, trained at R Franklin University of Med & Sci/Chicago Medical School (class of 2001). Their prescriptions cost Medicare Part D more than their services did: $131,474 for 344 claims, against $40,686 paid for services in 2024. National Marrow Donor Program reported $214.51 in payments in 2024, mostly food and beverage.

Overview

NPI	1235334137
Status	Active
Entity type	Individual
Credential	M.D.
Sole proprietor	No
NPI issued	Jun 19, 2007
Last updated in NPPES	Feb 19, 2020
Certified by provider	Feb 19, 2020

Specialties and licenses

Taxonomy	Code	License	State
Internal Medicine, Hematology Primary	207RH0000X	4301116418	MI
Internal Medicine	207R00000X	4301116418	MI
Internal Medicine, Hematology	207RH0000X	036-109957	IL
Internal Medicine, Hematology & Oncology	207RH0003X	036-109957	IL

About license numbers in NPPES

Exclusion screening

List	Result	Details
HHS-OIG LEIE · Nov 10, 2026	No match	Checked by NPI and by name + state
North Carolina Medicaid · Nov 11, 2026	No match	—
New York OMIG · Nov 11, 2026	No match	—
Ohio Medicaid · Nov 11, 2026	No match	—
Pennsylvania Medicheck · Nov 11, 2026	No match	—
Washington HCA · Nov 11, 2026	No match	—

Official OIG search · How matching works ·Bulk check a roster

Medicare

Enrollment (PECOS)	Enrolled Practitioner - Hematology (MI)
Accepts assignment	Yes (participating)

Medicare services in 2024

Medicare patients	66
Services billed	444 across 15 procedure codes
Paid by Medicare	$40,686

Part D prescriptions in 2024

Prescriptions (claims)	344 · 509 30-day fills
Patients	35
Total drug cost	$131,474
Generic share	87% of claims

Medicare sources and data years

Education and affiliations

Medical school	R Franklin University of Med & Sci/Chicago Medical School
Graduation year	2001
Medicare specialty	Hematology
Secondary specialties	Hematology/Oncology, Internal Medicine
Telehealth	Offers telehealth