What is Jacek Zajac's specialty?

Jacek Zajac (NPI 1396817912) is a Medicare-billing provider whose primary specialty is Endocrinology in Lombard, IL.

Where does Jacek Zajac practice?

Jacek Zajac practices in Lombard, IL, based on the location reported in the CMS Medicare provider datasets for NPI 1396817912.

How much does Medicare pay Jacek Zajac?

Jacek Zajac (NPI 1396817912) received approximately $102K in total Medicare Part B payments, serving 444 beneficiaries, per the CMS Medicare Physician & Other Practitioners dataset.

PROVIDER PROFILE · NPI 1396817912

Jacek ZajacM.D.

EndocrinologyLombard, ILI

MEDICARE UTILIZATION · PART B · 2024

Total beneficiaries

605

Unique beneficiaries

—

Total services

1,183

Distinct HCPCS

Medicare payment

$100K

Peer benchmark

Total Medicare services vs. 262 Endocrinology providers in IL — above median (cohort median 1,061).

PRESCRIBING · PART D · 2024

Total Rx claims

5,790

Beneficiaries

—

Total drug cost

$2.0M

Distinct drugs

Brand share

43.8%

Top prescribed drugs

Metformin Hcl578 claims

Levothyroxine Sodium559 claims

Semaglutide370 claims

Dulaglutide263 claims

Empagliflozin262 claims

QUALITY · MIPS · 2024

No data available for this provider in 2024.

INDUSTRY PAYMENTS · OPEN PAYMENTS · 2025

Total received

$4K

Payment records

183

By payment type

Food and Beverage$4K

Education$63

Top paying entities

Food and Beverage$4K

Education$63

REFERRAL NETWORK

Where Jacek Zajac's patients come from & go

Directional shared-patient flow from Medicare claims — who sends patients to this provider (inbound) and where this provider's patients go next (outbound). 25 inbound referrers · 53 outbound destinations.

Receives referrals from

Inbound — who sends patients here

Physician	Patients	Visits
John Cahill Interventional Cardiology · Elmhurst, IL	28	73
Lawrence Barr Interventional Cardiology · Elmhurst, IL	28	75
SCHULTZ, KURT	26	79
LOYOLA UNIVERSITY MEDICAL CENTER	26	138
Aheed Siddiqi Diagnostic Radiology · Downers Grove, IL	26	53
Liza Lopez Diagnostic Radiology · Downers Grove, IL	22	72
WADAS, MARIE	21	63
Lee Dennis Diagnostic Radiology · Elmhurst, IL	21	38
Phillip Cozzi Pulmonary Disease · Elmhurst, IL	18	95
Pratik Parikh Interventional Cardiology · Elmhurst, IL	18	65
WEINBERG, JEROLD	18	28
Rajeev Bhorade Diagnostic Radiology · Elmhurst, IL	17	40

Refers patients to

Outbound — where patients go next

Physician	Patients	Visits
ELMHURST MEMORIAL HOSPITAL	257	1,285
ADVOCATE HEALTH AND HOSPITALS CORPORATION	96	383
Terrence Swade Internal Medicine · Lombard, IL	49	180
David Wasserman Diagnostic Radiology · Elmhurst, IL	42	93
Aloyzas Pakalniskis Diagnostic Radiology · Elmhurst, IL	33	78
Cash Casey Clinical Cardiac Electrophysiology · Elmhurst, IL	31	113
WADAS, MARIE	30	83
Vivek Dave Diagnostic Radiology · Elmhurst, IL	30	59
WEINBERG, JEROLD	29	74
SCHULTZ, KURT	28	57
Elmer Murdock Interventional Cardiology · Elmhurst, IL	26	91
Superior Air-Ground Ambulance Service, Inc Ambulance Service Provider · Elmhurst, IL	26	38

Source: CMS Physician Shared Patient Patterns (30-day window, Medicare FFS). Direction = a beneficiary seen by the first provider, then the second, within 30 days; a proxy for referral, not a documented referral. Pairs with fewer than 11 shared beneficiaries are suppressed.

CROSS-REFERENCE

Related data on other Healthparse brands

ProviderScore

OIG/SAM exclusion screening, sanctions history

Healthparse Signals

Monitor this provider for changes — dated NPI change events