Healthcare provider profile · identity verified

Mark D. Horneffer, MD

Internal Medicine · WAUWATOSA, WI · NPI 1710928965

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
Atorvastatin Calcium	Atorvastatin Calcium	452	119
Losartan Potassium	Losartan Potassium	333	92
Metoprolol Succinate	Metoprolol Succinate	321	83
Amlodipine Besylate	Amlodipine Besylate	315	84
Levothyroxine Sodium	Levothyroxine Sodium	219	55
Rosuvastatin Calcium	Rosuvastatin Calcium	209	61
Metformin Hcl Er	Metformin Hcl	175	58
Pravastatin Sodium	Pravastatin Sodium	167	43
Tamsulosin Hcl	Tamsulosin Hcl	158	36
Eliquis	Apixaban	140	30
Omeprazole	Omeprazole	136	35
Pantoprazole Sodium	Pantoprazole Sodium	134	31
Escitalopram Oxalate	Escitalopram Oxalate	133	35
Spironolactone	Spironolactone	129	30
Celecoxib	Celecoxib	128	32
Lisinopril	Lisinopril	126	33
Finasteride	Finasteride	123	27
Mounjaro	Tirzepatide	113	21
Furosemide	Furosemide	112	29
Tramadol Hcl	Tramadol Hcl	112	25
Allopurinol	Allopurinol	110	29
Warfarin Sodium	Warfarin Sodium	106	15
Sertraline Hcl	Sertraline Hcl	99	19
Montelukast Sodium	Montelukast Sodium	94	23
Gabapentin	Gabapentin	92	22
Trazodone Hcl	Trazodone Hcl	81	21
Ipratropium Bromide	Ipratropium Bromide	80	23
Bupropion Xl	Bupropion Hcl	78	22
Donepezil Hcl	Donepezil Hcl	76	13
Ezetimibe	Ezetimibe	73	18
Albuterol Sulfate Hfa	Albuterol Sulfate	71	29
Lorazepam	Lorazepam	68	22
Meloxicam	Meloxicam	68	20
Buspirone Hcl	Buspirone Hcl	67	17
Memantine Hcl	Memantine Hcl	64	12
Clopidogrel	Clopidogrel Bisulfate	60	16
Famotidine	Famotidine	60	suppressed
Jardiance	Empagliflozin	60	16
Hydrochlorothiazide	Hydrochlorothiazide	54	16
Carvedilol	Carvedilol	49	17
Myrbetriq	Mirabegron	49	suppressed
Oxycodone-Acetaminophen	Oxycodone Hcl/Acetaminophen	49	suppressed
Potassium Chloride	Potassium Chloride	47	16
Pioglitazone Hcl	Pioglitazone Hcl	44	12
Metformin Hcl	Metformin Hcl	43	12
Duloxetine Hcl	Duloxetine Hcl	42	14
Mirtazapine	Mirtazapine	42	suppressed
Simvastatin	Simvastatin	41	13
Triamterene-Hydrochlorothiazid	Triamterene/Hydrochlorothiazid	41	16
Venlafaxine Hcl Er	Venlafaxine Hcl	41	11
Cephalexin	Cephalexin	40	27
Cyclobenzaprine Hcl	Cyclobenzaprine Hcl	40	13
Ozempic	Semaglutide	40	suppressed
Rybelsus	Semaglutide	39	suppressed
Hydralazine Hcl	Hydralazine Hcl	38	suppressed
Losartan-Hydrochlorothiazide	Losartan/Hydrochlorothiazide	37	12
Metoprolol Tartrate	Metoprolol Tartrate	36	11
Eplerenone	Eplerenone	35	suppressed
Hydrocodone-Acetaminophen	Hydrocodone/Acetaminophen	35	suppressed
Lantus Solostar	Insulin Glargine,hum.Rec.Anlog	35	suppressed
Lovastatin	Lovastatin	35	suppressed
Alfuzosin Hcl Er	Alfuzosin Hcl	34	suppressed
Triamcinolone Acetonide	Triamcinolone Acetonide	33	17
Baclofen	Baclofen	31	suppressed
Fluticasone Propionate	Fluticasone Propionate	31	11
Paroxetine Hcl	Paroxetine Hcl	30	suppressed
Trulicity	Dulaglutide	29	suppressed
Citalopram Hbr	Citalopram Hydrobromide	28	suppressed
Glipizide Er	Glipizide	27	suppressed
Lansoprazole	Lansoprazole	27	suppressed
Alendronate Sodium	Alendronate Sodium	25	suppressed
Naltrexone Hcl	Naltrexone Hcl	25	suppressed
Prednisone	Prednisone	25	19
Amiodarone Hcl	Amiodarone Hcl	23	suppressed
Atenolol	Atenolol	22	suppressed
Morphine Sulfate Er	Morphine Sulfate	22	suppressed
Ventolin Hfa	Albuterol Sulfate	22	suppressed
Synthroid	Levothyroxine Sodium	21	suppressed
Verapamil Er	Verapamil Hcl	21	suppressed
Acetaminophen-Codeine	Acetaminophen With Codeine	20	suppressed
Nano 2nd Gen Pen Needle	Pen Needle, Diabetic	20	suppressed
Sucralfate	Sucralfate	20	suppressed
Doxazosin Mesylate	Doxazosin Mesylate	19	suppressed
Glimepiride	Glimepiride	19	suppressed
Humalog	Insulin Lispro	19	suppressed
Arnuity Ellipta	Fluticasone Furoate	18	suppressed
Dicyclomine Hcl	Dicyclomine Hcl	18	suppressed
Fluoxetine Hcl	Fluoxetine Hcl	18	suppressed
Isosorbide Mononitrate Er	Isosorbide Mononitrate	18	suppressed
Januvia	Sitagliptin Phosphate	18	suppressed
Oxycodone Hcl	Oxycodone Hcl	18	suppressed
Pregabalin	Pregabalin	18	suppressed
Benazepril Hcl	Benazepril Hcl	17	suppressed
Ketoconazole	Ketoconazole	17	suppressed
Midodrine Hcl	Midodrine Hcl	17	suppressed
Nifedipine Er	Nifedipine	17	suppressed
Acetic Acid	Acetic Acid	16	suppressed
Amoxicillin	Amoxicillin	16	suppressed
Amoxicillin-Clavulanate Potass	Amoxicillin/Potassium Clav	16	14
Esomeprazole Magnesium	Esomeprazole Magnesium	16	suppressed
Stiolto Respimat	Tiotropium Br/Olodaterol Hcl	16	suppressed
Valacyclovir	Valacyclovir Hcl	16	suppressed
Zolpidem Tartrate	Zolpidem Tartrate	16	suppressed
Clonazepam	Clonazepam	15	suppressed
Humalog Kwikpen U-100	Insulin Lispro	15	suppressed
Alprazolam	Alprazolam	14	suppressed
Lidocaine	Lidocaine	14	suppressed
Topiramate	Topiramate	14	suppressed
Wixela Inhub	Fluticasone Propion/Salmeterol	14	suppressed
Carbidopa-Levodopa	Carbidopa/Levodopa	13	suppressed
Chlorhexidine Gluconate	Chlorhexidine Gluconate	13	suppressed
Enalapril Maleate	Enalapril Maleate	13	suppressed
Ibuprofen	Ibuprofen	13	suppressed
Nitroglycerin	Nitroglycerin	13	suppressed
Nortriptyline Hcl	Nortriptyline Hcl	13	suppressed
Nystatin	Nystatin	13	suppressed
Azithromycin	Azithromycin	12	11
Bumetanide	Bumetanide	12	suppressed
Diltiazem 24hr Er (Cd)	Diltiazem Hcl	12	suppressed
Doxycycline Monohydrate	Doxycycline Monohydrate	12	suppressed
Fluconazole	Fluconazole	12	suppressed
Olmesartan Medoxomil	Olmesartan Medoxomil	12	suppressed
Ondansetron Hcl	Ondansetron Hcl	12	suppressed
Oxycontin	Oxycodone Hcl	12	suppressed
Verapamil Sr	Verapamil Hcl	12	suppressed
Fluticasone-Salmeterol	Fluticasone Propion/Salmeterol	11	suppressed
Levemir	Insulin Detemir	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