Healthcare provider profile · identity verified

John Demask, D.O.

Family Practice · MINOOKA, IL · NPI 1174501134

Profile state: partd only Open Payments: 2025 Medicare Part D: 2024 Last identity check: 2026-08-10 Page data build: 2026-08-12

Verified facts

What the public records show

We did not find matching Open Payments records for this doctor in 2025.

These records do not establish that a payment influenced prescribing or medical care.

Payment overview · 2025

General Payments

We did not find matching Open Payments records for this doctor in the selected program year.

Separate record types

Research & Ownership

Research Payments (direct recipient): not present in the loaded data

Associated Research Funding (for example, named PI): not present in the loaded data

Ownership / Investment: not present in the loaded data

These categories are never added into the General Payments headline. Associated research funding must not be described as money the doctor personally received unless the source record supports that conclusion.

Analysis 1 · Payment-linked products

Products named in Open Payments records

No payment-linked product analysis is available because no matching General Payment records were found for the selected year.

Public prescribing for products named in payments

There is no explicit payment-product set available for a Part D comparison.

The presence of the same drug in both datasets does not show that a payment caused or influenced a prescription.

Analysis 2 · Same-company prescribing overlap

Drugs reported in other payments from the same company that also appear in Medicare Part D

This analysis is independent from products named on this doctor’s individual payment records. A row appears only when the exact Open Payments reporting entity paid this doctor, that same reporting entity reported the drug or biological on at least 10 loaded General Payment records involving at least 2 distinct recipient NPIs, and this doctor has the same non-generic brand in public Part D data. This does not mean the company owns or manufactures the drug.

There is no payer-company set available for this comparison.

These facts do not show that a payment was for the drug, that the company owns or manufactures the drug, or that a payment caused or influenced prescribing.

Public Medicare Part D data

Provider-and-drug rows loaded for 2024

BrandGenericClaimsBeneficiaries
Amlodipine BesylateAmlodipine Besylate25352
Levothyroxine SodiumLevothyroxine Sodium20538
HydrochlorothiazideHydrochlorothiazide20432
Atorvastatin CalciumAtorvastatin Calcium19340
LisinoprilLisinopril18731
Metformin HclMetformin Hcl16732
Losartan PotassiumLosartan Potassium14629
Hydrocodone-AcetaminophenHydrocodone/Acetaminophen12031
Metoprolol SuccinateMetoprolol Succinate11721
Rosuvastatin CalciumRosuvastatin Calcium11023
SimvastatinSimvastatin10623
AlprazolamAlprazolam10317
Pantoprazole SodiumPantoprazole Sodium10117
Amlodipine Besylate-BenazeprilAmlodipine Besylate/Benazepril9718
OmeprazoleOmeprazole9219
AllopurinolAllopurinol8914
Benazepril HclBenazepril Hcl8016
Benazepril-HydrochlorothiazideBenazepril/Hydrochlorothiazide63suppressed
Potassium ChloridePotassium Chloride6312
Tamsulosin HclTamsulosin Hcl6312
Amoxicillin-Clavulanate PotassAmoxicillin/Potassium Clav6148
Metoprolol TartrateMetoprolol Tartrate58suppressed
Pravastatin SodiumPravastatin Sodium5811
AzithromycinAzithromycin5241
Zolpidem TartrateZolpidem Tartrate47suppressed
Escitalopram OxalateEscitalopram Oxalate43suppressed
ClonazepamClonazepam39suppressed
PrednisonePrednisone3525
Esomeprazole MagnesiumEsomeprazole Magnesium34suppressed
Albuterol Sulfate HfaAlbuterol Sulfate32suppressed
Losartan-HydrochlorothiazideLosartan/Hydrochlorothiazide32suppressed
ClopidogrelClopidogrel Bisulfate28suppressed
FurosemideFurosemide28suppressed
MeloxicamMeloxicam28suppressed
Glipizide ErGlipizide27suppressed
Lisinopril-HydrochlorothiazideLisinopril/Hydrochlorothiazide27suppressed
Sertraline HclSertraline Hcl25suppressed
OzempicSemaglutide24suppressed
Acetaminophen-CodeineAcetaminophen With Codeine23suppressed
Alendronate SodiumAlendronate Sodium22suppressed
SynthroidLevothyroxine Sodium22suppressed
Montelukast SodiumMontelukast Sodium21suppressed
Ciprofloxacin HclCiprofloxacin Hcl2015
FenofibrateFenofibrate Nanocrystallized20suppressed
GlipizideGlipizide20suppressed
Nebivolol HclNebivolol Hcl20suppressed
BaclofenBaclofen19suppressed
Nifedipine ErNifedipine19suppressed
DiazepamDiazepam17suppressed
Paroxetine HclParoxetine Hcl17suppressed
Tramadol HclTramadol Hcl16suppressed
Triamterene-HydrochlorothiazidTriamterene/Hydrochlorothiazid16suppressed
FinasterideFinasteride15suppressed
Metformin Hcl ErMetformin Hcl15suppressed
TestosteroneTestosterone15suppressed
XareltoRivaroxaban15suppressed
AtenololAtenolol14suppressed
Diclofenac Sodium ErDiclofenac Sodium14suppressed
EliquisApixaban14suppressed
GabapentinGabapentin14suppressed
Bupropion XlBupropion Hcl13suppressed
CarvedilolCarvedilol13suppressed
Cyclobenzaprine HclCyclobenzaprine Hcl13suppressed
Sulfamethoxazole-TrimethoprimSulfamethoxazole/Trimethoprim1311
CefadroxilCefadroxil1211
Diclofenac SodiumDiclofenac Sodium12suppressed
EzetimibeEzetimibe12suppressed
Fludrocortisone AcetateFludrocortisone Acetate12suppressed
Hydroxychloroquine SulfateHydroxychloroquine Sulfate12suppressed
MethylprednisoloneMethylprednisolone1211
MupirocinMupirocin12suppressed
Trazodone HclTrazodone Hcl12suppressed
Clonidine HclClonidine Hcl11suppressed
LansoprazoleLansoprazole11suppressed
Phenytoin Sodium ExtendedPhenytoin Sodium Extended11suppressed
Triamcinolone AcetonideTriamcinolone Acetonide11suppressed

Timeline

Payment and prescribing data by year

Open Payments and Medicare Part D may refer to different years. They are shown separately rather than aligned as if they describe the same period.

YearGeneral PaymentsMain payerExplicit productsCompany overlapsPart D coverage
2025
2024 Complete

Questions to ask

Questions you could discuss with your doctor

These are general questions generated from reviewed templates. They are not personalized medical advice.

Sources and limitations

How to read this page

Loaded source releases

DatasetYearPublicationSource
CMS Open Payments — General Payments 2025 2026-06-30 Original source
Medicare Part D Prescribers by Provider and Drug 2024 2026-05-06 Original source
NPPES Data Dissemination V2 current / reference data 2026-08-10 Original source

Methodology version: 2.1

Editorial template version: 2.4

Product contract version: 2.0

Schema version: 0.7.0

Page data build: 2026-08-12T23:34:59.370714+00:00

Publication policy: eligible for indexing after public-launch controls are enabled

Full methodology · Questions & answers · Report a possible error