Doctor profile · Federal record

Dr. John Maciejewski, M.D.

Hematology (Internal Medicine) Physician (CMS: Hematology) · Internal Medicine Physician · Hematology (Internal Medicine) Physician · Hematology & Oncology Physician · Ann Arbor, MI

  • NPI 1235334137
  • Accepts Medicare
  • 25 yrs in practice
  • Licensed in 2 states
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
1500 E Medical Center Dr
Ann Arbor, MI 481095000
(734) 936-4000
Mailing address
3621 S State St
Ann Arbor, MI 481081633

Credentials & registration

NPPES · NUCC
NPI registered
June 2007 — 19 yrs on file
Profile last updated
February 19, 2020
Year of graduation
2001 — 25 yrs since
Specialty taxonomy
207RH0000X — NUCC code
State licenses (2)
Michigan #4301116418 · Illinois #036-109957

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1235334137. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
321
Distinct HCPCS
5
Medicare allowed
$41,504
HCPCS Description Services Patients Avg allowed
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 182 31 $120
99215 Established patient office or other outpatient visit, 40-54 minutes 92 28 $145
99239 Hospital discharge day management, more than 30 minutes 18 17 $117
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 17 13 $177
99214 Established patient office or other outpatient visit, 30-39 minutes 12 11 $99

In context: peer comparison

Among 11 peers in this city , average services per provider: 57. This provider delivers 5.6× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$215
Transactions
1
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
National Marrow Donor Program 1 $214.51

By nature of payment

Food and Beverage
$215

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
129
Patients
11
Total drug cost
$332,576
Drug Type Claims Patients Total cost
Acyclovir Generic 34 11 $1,040
Azithromycin Generic 24 0 $311
Ursodiol Generic 24 0 $2,615
Jakafi (Ruxolitinib Phosphate) Brand 13 0 $232,966
Cresemba (Isavuconazonium Sulfate) Brand 12 0 $76,955
Magnesium Sulfate Generic 11 0 $165
Posaconazole Generic 11 0 $18,524

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. John Maciejewski's medical specialty?
Dr. John Maciejewski practices Hematology (Internal Medicine) Physician in Ann Arbor, MI.
Where does Dr. John Maciejewski practice?
Dr. John Maciejewski practices at 1500 E Medical Center Dr, Ann Arbor, MI 481095000. Office phone: 7349364000.
What is Dr. John Maciejewski's NPI?
Dr. John Maciejewski's National Provider Identifier (NPI) is 1235334137, issued by NPPES.
Does Dr. John Maciejewski accept Medicare assignment?
Yes. Dr. John Maciejewski accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. John Maciejewski commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233); Established patient office or other outpatient visit (HCPCS 99215); Hospital discharge day management (HCPCS 99239). Source: CMS Medicare Physician & Other Practitioners file.