Healthcare provider profile · identity verified

Mark W Stolar, M.D.

Internal Medicine · WOODSTOCK, IL · NPI 1396784591

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

Brand	Generic	Claims	Beneficiaries
Levothyroxine Sodium	Levothyroxine Sodium	516	159
Atorvastatin Calcium	Atorvastatin Calcium	444	146
Rosuvastatin Calcium	Rosuvastatin Calcium	303	89
Amlodipine Besylate	Amlodipine Besylate	298	98
Metoprolol Succinate	Metoprolol Succinate	242	75
Losartan Potassium	Losartan Potassium	199	66
Ozempic	Semaglutide	190	42
Hydrocodone-Acetaminophen	Hydrocodone/Acetaminophen	182	49
Pantoprazole Sodium	Pantoprazole Sodium	180	56
Alprazolam	Alprazolam	179	55
Gabapentin	Gabapentin	178	62
Omeprazole	Omeprazole	164	54
Lisinopril	Lisinopril	155	48
Metformin Hcl Er	Metformin Hcl	145	45
Bupropion Xl	Bupropion Hcl	144	36
Spironolactone	Spironolactone	116	38
Tamsulosin Hcl	Tamsulosin Hcl	104	36
Ezetimibe	Ezetimibe	103	34
Tramadol Hcl	Tramadol Hcl	103	27
Allopurinol	Allopurinol	100	24
Meloxicam	Meloxicam	100	31
Metformin Hcl	Metformin Hcl	97	34
Pioglitazone Hcl	Pioglitazone Hcl	95	31
Hydrochlorothiazide	Hydrochlorothiazide	94	30
Montelukast Sodium	Montelukast Sodium	94	25
Furosemide	Furosemide	92	39
Prednisone	Prednisone	92	36
Zolpidem Tartrate	Zolpidem Tartrate	92	28
Pregabalin	Pregabalin	91	30
Liothyronine Sodium	Liothyronine Sodium	89	27
Jardiance	Empagliflozin	86	25
Methylprednisolone	Methylprednisolone	85	66
Trazodone Hcl	Trazodone Hcl	83	27
Glimepiride	Glimepiride	81	30
Lorazepam	Lorazepam	81	25
Simvastatin	Simvastatin	79	28
Trulicity	Dulaglutide	77	17
Pravastatin Sodium	Pravastatin Sodium	74	24
Clonazepam	Clonazepam	70	17
Eliquis	Apixaban	70	21
Duloxetine Hcl	Duloxetine Hcl	67	22
Lantus Solostar	Insulin Glargine,hum.Rec.Anlog	67	24
Metoprolol Tartrate	Metoprolol Tartrate	67	19
Carvedilol	Carvedilol	64	24
Synthroid	Levothyroxine Sodium	64	20
Farxiga	Dapagliflozin Propanediol	62	12
Celecoxib	Celecoxib	60	15
Citalopram Hbr	Citalopram Hydrobromide	60	17
Clopidogrel	Clopidogrel Bisulfate	60	17
Sertraline Hcl	Sertraline Hcl	58	18
Azithromycin	Azithromycin	56	45
Novolog Flexpen	Insulin Aspart	55	17
Tresiba Flextouch U-100	Insulin Degludec	55	12
Fluoxetine Hcl	Fluoxetine Hcl	54	13
Fluticasone Propionate	Fluticasone Propionate	53	26
Albuterol Sulfate Hfa	Albuterol Sulfate	48	27
Mounjaro	Tirzepatide	48	suppressed
Potassium Chloride	Potassium Chloride	48	21
Fenofibrate	Fenofibrate	46	suppressed
Atenolol	Atenolol	45	13
Armour Thyroid	Thyroid,pork	44	suppressed
Escitalopram Oxalate	Escitalopram Oxalate	43	16
Losartan-Hydrochlorothiazide	Losartan/Hydrochlorothiazide	41	15
Lisinopril-Hydrochlorothiazide	Lisinopril/Hydrochlorothiazide	40	14
Repaglinide	Repaglinide	39	13
Xarelto	Rivaroxaban	39	suppressed
Humalog Kwikpen U-100	Insulin Lispro	38	13
Januvia	Sitagliptin Phosphate	38	13
Basaglar Kwikpen U-100	Insulin Glargine,hum.Rec.Anlog	36	suppressed
Irbesartan	Irbesartan	36	suppressed
Valsartan-Hydrochlorothiazide	Valsartan/Hydrochlorothiazide	36	suppressed
Cyclobenzaprine Hcl	Cyclobenzaprine Hcl	35	13
Diazepam	Diazepam	35	suppressed
Nano 2nd Gen Pen Needle	Pen Needle, Diabetic	34	12
Oxycodone Hcl	Oxycodone Hcl	34	suppressed
Tizanidine Hcl	Tizanidine Hcl	34	13
Diltiazem 24hr Er (Cd)	Diltiazem Hcl	33	12
Famotidine	Famotidine	32	14
Hydrocortisone	Hydrocortisone	32	suppressed
Nitrofurantoin Mono-Macro	Nitrofurantoin Monohyd/M-Cryst	32	28
Venlafaxine Hcl Er	Venlafaxine Hcl	32	suppressed
Rybelsus	Semaglutide	31	suppressed
Doxycycline Hyclate	Doxycycline Hyclate	29	18
Ultra-Fine Short Pen Needle	Pen Needle, Diabetic	29	suppressed
Valsartan	Valsartan	29	11
Isosorbide Mononitrate Er	Isosorbide Mononitrate	28	suppressed
Lansoprazole	Lansoprazole	28	suppressed
Triamterene-Hydrochlorothiazid	Triamterene/Hydrochlorothiazid	28	suppressed
Buspirone Hcl	Buspirone Hcl	26	suppressed
Doxepin Hcl	Doxepin Hcl	26	suppressed
Paroxetine Hcl	Paroxetine Hcl	26	suppressed
Valacyclovir	Valacyclovir Hcl	26	16
Toujeo Solostar	Insulin Glargine,hum.Rec.Anlog	25	11
Warfarin Sodium	Warfarin Sodium	25	suppressed
Toujeo Max Solostar	Insulin Glargine,hum.Rec.Anlog	23	suppressed
Ciprofloxacin Hcl	Ciprofloxacin Hcl	22	21
Doxazosin Mesylate	Doxazosin Mesylate	22	suppressed
Amlodipine Besylate-Benazepril	Amlodipine Besylate/Benazepril	21	suppressed
Amoxicillin-Clavulanate Potass	Amoxicillin/Potassium Clav	21	16
Baclofen	Baclofen	21	suppressed
Colchicine	Colchicine	21	suppressed
Diclofenac Sodium	Diclofenac Sodium	21	suppressed
Ibandronate Sodium	Ibandronate Sodium	21	11
Naproxen	Naproxen	20	suppressed
Prochlorperazine Maleate	Prochlorperazine Maleate	20	suppressed
Repatha Sureclick	Evolocumab	20	suppressed
Breo Ellipta	Fluticasone/Vilanterol	19	suppressed
Cephalexin	Cephalexin	19	19
Clonidine Hcl	Clonidine Hcl	19	suppressed
Meclizine Hcl	Meclizine Hcl	19	suppressed
Testosterone	Testosterone	19	suppressed
Torsemide	Torsemide	19	suppressed
Verapamil Er	Verapamil Hcl	19	suppressed
Alendronate Sodium	Alendronate Sodium	18	suppressed
Amitriptyline Hcl	Amitriptyline Hcl	18	suppressed
Donepezil Hcl	Donepezil Hcl	18	suppressed
Fenofibrate	Fenofibrate Nanocrystallized	18	suppressed
Finasteride	Finasteride	18	suppressed
Humalog	Insulin Lispro	18	suppressed
Lamotrigine	Lamotrigine	18	suppressed
Lumigan	Bimatoprost	18	suppressed
Myrbetriq	Mirabegron	18	suppressed
Nabumetone	Nabumetone	18	suppressed
Oxybutynin Chloride Er	Oxybutynin Chloride	18	suppressed
Paxlovid	Nirmatrelvir/Ritonavir	18	17
Temazepam	Temazepam	18	suppressed
Vitamin D2	Ergocalciferol (Vitamin D2)	18	suppressed
Alfuzosin Hcl Er	Alfuzosin Hcl	17	suppressed
Azelastine Hcl	Azelastine Hcl	17	suppressed
Bumetanide	Bumetanide	17	suppressed
Trelegy Ellipta	Fluticasone/Umeclidin/Vilanter	17	suppressed
Trueplus Pen Needle	Pen Needle, Diabetic	17	suppressed
Wegovy	Semaglutide	17	suppressed
Amoxicillin	Amoxicillin	16	14
Benazepril Hcl	Benazepril Hcl	16	suppressed
Bisoprolol-Hydrochlorothiazide	Bisoprolol/Hydrochlorothiazide	16	suppressed
Fluconazole	Fluconazole	16	11
Oxybutynin Chloride	Oxybutynin Chloride	16	suppressed
Oxycodone-Acetaminophen	Oxycodone Hcl/Acetaminophen	16	11
Tresiba Flextouch U-200	Insulin Degludec	16	suppressed
Ultra-Fine Mini Pen Needle	Pen Needle, Diabetic	16	suppressed
Dicyclomine Hcl	Dicyclomine Hcl	15	suppressed
Estradiol (Twice Weekly)	Estradiol	15	suppressed
Folic Acid	Folic Acid	15	suppressed
Hydroxyzine Hcl	Hydroxyzine Hcl	15	suppressed
Ondansetron Odt	Ondansetron	15	suppressed
Triamcinolone Acetonide	Triamcinolone Acetonide	15	suppressed
Hydromorphone Hcl	Hydromorphone Hcl	14	suppressed
Janumet	Sitagliptin Phos/Metformin Hcl	14	suppressed
Levetiracetam	Levetiracetam	14	suppressed
Lidocaine	Lidocaine	14	suppressed
Memantine Hcl	Memantine Hcl	14	suppressed
Quetiapine Fumarate	Quetiapine Fumarate	14	suppressed
Ropinirole Hcl	Ropinirole Hcl	14	suppressed
Tolterodine Tartrate Er	Tolterodine Tartrate	14	suppressed
Topiramate	Topiramate	14	suppressed
Tradjenta	Linagliptin	14	suppressed
Carisoprodol	Carisoprodol	13	suppressed
Fluticasone-Salmeterol	Fluticasone Propion/Salmeterol	13	suppressed
Zaleplon	Zaleplon	13	suppressed
Brilinta	Ticagrelor	12	suppressed
Dextroamphetamine-Amphetamine	Dextroamphetamine/Amphetamine	12	suppressed
Droplet Pen Needle	Pen Needle, Diabetic	12	suppressed
Eszopiclone	Eszopiclone	12	suppressed
Glycopyrrolate	Glycopyrrolate	12	suppressed
Modafinil	Modafinil	12	suppressed
Aripiprazole	Aripiprazole	11	suppressed
Butalbital-Acetaminophen-Caffe	Butalb/Acetaminophen/Caffeine	11	suppressed
Epinephrine	Epinephrine	11	suppressed
Hydralazine Hcl	Hydralazine Hcl	11	suppressed
Levocetirizine Dihydrochloride	Levocetirizine Dihydrochloride	11	suppressed
Lovastatin	Lovastatin	11	suppressed
Pramipexole Dihydrochloride	Pramipexole Di-Hcl	11	suppressed
Sumatriptan Succinate	Sumatriptan Succinate	11	suppressed
Thyroid	Thyroid,pork	11	suppressed
Xanax	Alprazolam	11	suppressed

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.

Year	General Payments	Main payer	Explicit products	Company overlaps	Part D coverage
2025	—	—	—	—	—
2024	—	—	—	—	Complete

Questions to ask

Questions you could discuss with your doctor

Are there reasonable alternatives I should understand when we discuss treatment options?
How should I interpret the industry-payment records shown here in the context of my care?

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

Sources and limitations

How to read this page

Payment and Medicare prescribing data can cover different years; every comparison shows both years explicitly.
Part D does not represent a doctor’s entire practice; it excludes many patients and is subject to CMS public-release thresholds.
Company–drug relationships must have an auditable source, a precise relationship type, and a valid evidence period. Unresolved mappings are not published.
Generic drug claims are not attributed to a specific manufacturer without manufacturer-level evidence.
When a source extract is incomplete, missing rows are never treated as proof of no payments or no prescriptions.

Loaded source releases

Dataset	Year	Publication	Source
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