Doctor profile · Federal record

Dr. Irena Zalewska, MD

Gastroenterology Physician (CMS: Gastroenterology) · St Clair Shores, MI

  • NPI 1407846751
  • Accepts Medicare
  • MIPS 75.0 / 100 · 2023
  • 28 yrs in practice
  • Female
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
28963 Little Mack Ave, GI Medicine Associates PC Suite 101
St Clair Shores, MI 480813015
(586) 447-0700
fax (586) 498-0707

Credentials & registration

NPPES · NUCC
NPI registered
October 2005 — 21 yrs on file
Profile last updated
June 29, 2010
Year of graduation
1998 — 28 yrs since
Specialty taxonomy
207RG0100X — NUCC code
State license (1)
Michigan #4301072116
Medicaid
MI #459576110

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1407846751. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
971
Distinct HCPCS
10
Medicare allowed
$109,343
HCPCS Description Services Patients Avg allowed
88305 Pathology examination of tissue using a microscope, intermediate complexity 400 180 $35
99214 Established patient office or other outpatient visit, 30-39 minutes 142 97 $129
45385 Removal of polyps or growths of large bowel using an endoscope with mechanical snare 123 123 $257
43239 Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 89 84 $112
45380 Biopsy of large bowel using a flexible endoscope 75 75 $114
99213 Established patient office or other outpatient visit, 20-29 minutes 53 44 $91
99204 New patient office or other outpatient visit, 45-59 minutes 34 34 $164
G0105 Colorectal cancer screening; colonoscopy on individual at high risk 31 31 $189
G0121 Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk 13 13 $190
91110 Imaging of digestive tract done from the inside of the digestive tract 11 11 $742

In context: peer comparison

Among 4 peers in this city , average services per provider: 73. This provider delivers 13× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$1,965
Transactions
81
Manufacturers
15
Payer (manufacturer) Industry Txns Amount
ABBVIE INC. 23 $524.46
Janssen Biotech, Inc. 15 $504.50
Takeda Pharmaceuticals U.S.A., Inc. 11 $173.95
Janssen Scientific Affairs, LLC 2 $159.66
Celgene Corporation 9 $142.82
Gilead Sciences, Inc. 6 $105.30
GENZYME CORPORATION 3 $67.46
PFIZER INC. 3 $59.56
Salix Pharmaceuticals, a division of Bausch Health US, LLC 2 $49.94
Regeneron Healthcare Solutions, Inc. 2 $41.71
Ipsen Biopharmaceuticals, Inc 1 $31.16
QOL Medical, LLC 1 $26.35
Intercept Pharmaceuticals, Inc. 1 $17.52
Lilly USA, LLC 1 $17.37
Amgen Inc. 1 $15.40

By nature of payment

Food and Beverage
$1,965

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
942
Patients
375
Total drug cost
$807,845
Drug Type Claims Patients Total cost
Famotidine Generic 188 86 $3,248
Pantoprazole Sodium Generic 186 72 $3,855
Omeprazole Generic 117 50 $3,012
Sucralfate Generic 95 39 $16,838
Rabeprazole Sodium Generic 76 42 $7,245
Mesalamine Generic 51 18 $25,981
Cholestyramine (Cholestyramine (With Sugar)) Brand 44 22 $4,885
Dicyclomine Hcl Generic 32 0 $674
Gavilyte-G (Peg3350/Sod Sulf,bicarb,cl/Kcl) Brand 32 32 $620
Stelara (Ustekinumab) Brand 29 0 $719,240

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Irena Zalewska's medical specialty?
Dr. Irena Zalewska practices Gastroenterology Physician in St Clair Shores, MI.
Where does Dr. Irena Zalewska practice?
Dr. Irena Zalewska practices at 28963 Little Mack Ave, St Clair Shores, MI 480813015. Office phone: 5864470700.
What is Dr. Irena Zalewska's NPI?
Dr. Irena Zalewska's National Provider Identifier (NPI) is 1407846751, issued by NPPES.
Does Dr. Irena Zalewska accept Medicare assignment?
Yes. Dr. Irena Zalewska accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Irena Zalewska commonly perform?
Top Medicare-reported procedures in 2023: Pathology examination of tissue using a microscope, intermediate complexity (HCPCS 88305); Established patient office or other outpatient visit (HCPCS 99214); Removal of polyps or growths of large bowel using an endoscope with mechanical snare (HCPCS 45385). Source: CMS Medicare Physician & Other Practitioners file.