John Joseph Maciejewski, M.D.
Hematology (Internal Medicine) Physician · Ann Arbor, MI
John Joseph Maciejewski, M.D. is a hematology (internal medicine) physician with a practice address in Ann Arbor, Michigan, and NPI 1235334137, issued on Jun 19, 2007. Check the license (Michigan 4301116418, as entered in NPPES) on the Michigan Board of Medicine (LARA); the Medicare figures below come from public CMS files.
- Name
- John Joseph Maciejewski
- Credential
- M.D.
- Primary taxonomy
- Hematology (Internal Medicine) Physician 207RH0000X
- License numbers
- 4301116418 MI
036-109957 IL
Self-reported in NPPES; status is on the state search - Practice location
- 1500 E Medical Center Dr, Ann Arbor, MI 48109
- Phone
- (734) 936-4000
- Enumerated
- Jun 19, 2007
- Record last updated
- Feb 19, 2020 (not updated in 6 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20181215000116); accepts Medicare assignment
- Medical or professional school
- R Franklin University Of Med & Sci/Chicago Medical School, 2001
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest hematology (internal medicine) physician records → All 57 in Michigan → Look up another NPI →
Also registered at 1500 E Medical Center Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Anjelica Abate, MDDiagnostic Radiology Physician1841819216
- Nicole Abbott, CRNACertified Registered Nurse Anesthetist1790329860
- Ahmed Abdel-Latif, M.D.Interventional Cardiology Physician1518181239
Verify John Joseph Maciejewski in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMichigan Board of Medicine (LARA)
Search for license 4301116418Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
31% fewer Medicare Part D claims than the average hematology (internal medicine) physician in 2024
344 Medicare Part D claims for 35 beneficiaries, against an average of 496 among the 1,036 providers of this specialty who prescribed in Part D. Brand-name drugs were 13% of claims.
Most prescribed
- Acyclovir63 claims
- Azithromycin30 claims
- Ursodiol26 claims
- Sulfamethoxazole-Trimethoprim20 claims
- Levofloxacin19 claims
- Fluconazole15 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Industry payments in 2024: $214.51
1 payment: food and beverage; the largest payer was National Marrow Donor Program. The 721 providers of this specialty with any payment received $13,778.35 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Regents OF The University OF MichiganAnn Arbor, MI
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
John Joseph Maciejewski among 57 hematology (internal medicine) physician records in Michigan
John Joseph Maciejewski, M.D. is one of 57 hematology (internal medicine) physician records with a practice address in Michigan. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 39% of them.
- NPI issued2007 · 39% of these records are older, 51% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 79% of these records are
- Graduated2001 · median 2007 among the 45 with a school on file
- Record last updated2020 · 46% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RH0000X and a Michigan practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Hematology (Internal Medicine) Physician providers in Michigan
There are 57 hematology (internal medicine) physician records in Michigan.
All 57 in Michigan → Every provider in Ann Arbor → Hematology (Internal Medicine) Physician nationwide →
The 8 hematology (internal medicine) physician records with the nearest ZIP codes
- Asra Ahmed, MDAnn Arbor, MI 481091013093079
- Dale Bixby, MDAnn Arbor, MI 481091952423816
- Paula Bockenstedt, MDAnn Arbor, MI 481091366528325
- Erica Campagnaro, MDAnn Arbor, MI 481091891854683
- Mark Chiang, MDAnn Arbor, MI 481091720034986
- Alice Cusick, M.D.Ann Arbor, MI 481091407824154
- Michael Deininger, MDAnn Arbor, MI 481091932115524
- Jennifer Griggs, MD, MPHAnn Arbor, MI 481091700949609
Common questions
What is John Joseph Maciejewski, M.D.'s NPI number?
John Joseph Maciejewski, M.D.'s National Provider Identifier (NPI) is 1235334137, issued on Jun 19, 2007. An NPI identifies a provider in billing; it is not a license.
Where is John Joseph Maciejewski, M.D. located?
The NPPES record lists a practice address at 1500 E Medical Center Dr, Ann Arbor, MI, 48109. Phone: (734) 936-4000. Providers update this record themselves, so call before visiting.
How can I verify John Joseph Maciejewski, M.D.'s license?
NPPES lists Michigan license number 4301116418, as entered by the provider. Search the Michigan Board of Medicine (LARA) at https://aca-prod.accela.com/MILARA/GeneralProperty/PropertyLookUp.aspx?isLicensee=Y&TabName=APO. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does John Joseph Maciejewski, M.D. prescribe under Medicare Part D?
In 2024, John Joseph Maciejewski, M.D. had 344 Medicare Part D claims for 35 beneficiaries; the average among hematology (internal medicine) physician prescribers was 496. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.