Healthcare provider profile · identity verified

Thomas Keith Duncan, MD

Internal Medicine · NEENAH, WI · NPI 1588641039

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	479	125
Amlodipine Besylate	Amlodipine Besylate	367	105
Omeprazole	Omeprazole	337	91
Lisinopril	Lisinopril	336	90
Hydrochlorothiazide	Hydrochlorothiazide	280	81
Levothyroxine Sodium	Levothyroxine Sodium	274	59
Metoprolol Succinate	Metoprolol Succinate	240	69
Losartan Potassium	Losartan Potassium	222	65
Simvastatin	Simvastatin	220	59
Metformin Hcl	Metformin Hcl	213	55
Furosemide	Furosemide	205	57
Gabapentin	Gabapentin	174	38
Pantoprazole Sodium	Pantoprazole Sodium	174	43
Tamsulosin Hcl	Tamsulosin Hcl	166	51
Pravastatin Sodium	Pravastatin Sodium	164	41
Warfarin Sodium	Warfarin Sodium	158	24
Metoprolol Tartrate	Metoprolol Tartrate	156	43
Rosuvastatin Calcium	Rosuvastatin Calcium	152	42
Finasteride	Finasteride	148	39
Eliquis	Apixaban	141	35
Potassium Chloride	Potassium Chloride	127	38
Allopurinol	Allopurinol	112	32
Ezetimibe	Ezetimibe	111	29
Montelukast Sodium	Montelukast Sodium	105	30
Metformin Hcl Er	Metformin Hcl	93	27
Cyclobenzaprine Hcl	Cyclobenzaprine Hcl	92	16
Clopidogrel	Clopidogrel Bisulfate	90	28
Sertraline Hcl	Sertraline Hcl	84	25
Doxazosin Mesylate	Doxazosin Mesylate	82	25
Albuterol Sulfate Hfa	Albuterol Sulfate	81	39
Glipizide Er	Glipizide	81	18
Fluoxetine Hcl	Fluoxetine Hcl	80	16
Donepezil Hcl	Donepezil Hcl	79	20
Jardiance	Empagliflozin	74	21
Glipizide	Glipizide	70	22
Diclofenac Sodium	Diclofenac Sodium	60	20
Venlafaxine Hcl Er	Venlafaxine Hcl	55	12
Duloxetine Hcl	Duloxetine Hcl	54	13
Dicyclomine Hcl	Dicyclomine Hcl	50	16
Lovastatin	Lovastatin	48	suppressed
Atenolol	Atenolol	47	13
Hydrocodone-Acetaminophen	Hydrocodone/Acetaminophen	47	16
Alprazolam	Alprazolam	45	13
Lisinopril-Hydrochlorothiazide	Lisinopril/Hydrochlorothiazide	45	12
Spironolactone	Spironolactone	45	13
Fluticasone-Salmeterol	Fluticasone Propion/Salmeterol	43	12
Triamcinolone Acetonide	Triamcinolone Acetonide	43	25
Escitalopram Oxalate	Escitalopram Oxalate	41	12
Famotidine	Famotidine	41	suppressed
Trazodone Hcl	Trazodone Hcl	41	12
Ozempic	Semaglutide	40	14
Fluticasone Propionate	Fluticasone Propionate	39	15
Ketoconazole	Ketoconazole	39	19
Tramadol Hcl	Tramadol Hcl	37	22
Citalopram Hbr	Citalopram Hydrobromide	36	11
Desmopressin Acetate	Desmopressin Acetate	36	suppressed
Diazepam	Diazepam	35	suppressed
Celecoxib	Celecoxib	34	suppressed
Gemfibrozil	Gemfibrozil	34	suppressed
Meloxicam	Meloxicam	33	suppressed
Memantine Hcl	Memantine Hcl	33	suppressed
Oxybutynin Chloride Er	Oxybutynin Chloride	33	suppressed
Fluconazole	Fluconazole	32	11
Lantus Solostar	Insulin Glargine,hum.Rec.Anlog	32	suppressed
Levetiracetam	Levetiracetam	32	suppressed
Synthroid	Levothyroxine Sodium	31	suppressed
Prednisone	Prednisone	30	15
Primidone	Primidone	30	suppressed
Isosorbide Mononitrate Er	Isosorbide Mononitrate	29	suppressed
Alendronate Sodium	Alendronate Sodium	28	12
Amoxicillin	Amoxicillin	26	19
Nitroglycerin	Nitroglycerin	26	22
Amitriptyline Hcl	Amitriptyline Hcl	25	suppressed
Baclofen	Baclofen	25	suppressed
Azithromycin	Azithromycin	24	22
Oxybutynin Chloride	Oxybutynin Chloride	24	suppressed
Xarelto	Rivaroxaban	23	suppressed
Zolpidem Tartrate	Zolpidem Tartrate	23	suppressed
Enalapril Maleate	Enalapril Maleate	22	suppressed
Pregabalin	Pregabalin	22	suppressed
Torsemide	Torsemide	22	suppressed
Verapamil Er	Verapamil Hcl	22	suppressed
Clonazepam	Clonazepam	21	suppressed
Hydralazine Hcl	Hydralazine Hcl	21	suppressed
Metronidazole	Metronidazole	21	suppressed
Myrbetriq	Mirabegron	21	suppressed
Ropinirole Hcl	Ropinirole Hcl	21	suppressed
Valacyclovir	Valacyclovir Hcl	21	suppressed
Bupropion Xl	Bupropion Hcl	20	suppressed
Lorazepam	Lorazepam	20	suppressed
Losartan-Hydrochlorothiazide	Losartan/Hydrochlorothiazide	19	suppressed
Paroxetine Hcl	Paroxetine Hcl	19	suppressed
Trulicity	Dulaglutide	19	suppressed
Aripiprazole	Aripiprazole	18	suppressed
Budesonide Ec	Budesonide	18	suppressed
Fenofibrate	Fenofibrate	18	suppressed
Hydroxyzine Hcl	Hydroxyzine Hcl	18	suppressed
Oxycodone Hcl	Oxycodone Hcl	18	suppressed
Valsartan	Valsartan	18	suppressed
Clonidine Hcl	Clonidine Hcl	17	suppressed
Irbesartan-Hydrochlorothiazide	Irbesartan/Hydrochlorothiazide	17	suppressed
Sildenafil Citrate	Sildenafil Citrate	17	suppressed
Sulfamethoxazole-Trimethoprim	Sulfamethoxazole/Trimethoprim	17	15
Benazepril Hcl	Benazepril Hcl	16	suppressed
Buspirone Hcl	Buspirone Hcl	16	suppressed
Carvedilol	Carvedilol	16	suppressed
Cephalexin	Cephalexin	16	14
Methylprednisolone	Methylprednisolone	16	15
Propranolol Hcl Er	Propranolol Hcl	16	suppressed
Tizanidine Hcl	Tizanidine Hcl	16	suppressed
Alcohol Prep Pads	Alcohol Antiseptic Pads	15	suppressed
Ciprofloxacin Hcl	Ciprofloxacin Hcl	15	11
Januvia	Sitagliptin Phosphate	15	suppressed
Mirtazapine	Mirtazapine	15	suppressed
Triamterene-Hydrochlorothiazid	Triamterene/Hydrochlorothiazid	15	suppressed
Wixela Inhub	Fluticasone Propion/Salmeterol	15	suppressed
Budesonide-Formoterol Fumarate	Budesonide/Formoterol Fumarate	14	suppressed
Fenofibrate	Fenofibrate Nanocrystallized	14	suppressed
Loperamide	Loperamide Hcl	14	suppressed
Carbidopa-Levodopa	Carbidopa/Levodopa	13	suppressed
Mounjaro	Tirzepatide	13	suppressed
Premarin	Estrogens, Conjugated	13	suppressed
Risperidone	Risperidone	13	suppressed
Amlodipine Besylate-Benazepril	Amlodipine Besylate/Benazepril	12	suppressed
Aspirin-Dipyridamole Er	Aspirin/Dipyridamole	12	suppressed
Dextroamphetamine-Amphetamine	Dextroamphetamine/Amphetamine	12	suppressed
Diltiazem Hcl	Diltiazem Hcl	12	suppressed
Doxycycline Hyclate	Doxycycline Hyclate	12	12
Latanoprost	Latanoprost	12	suppressed
Omega-3 Acid Ethyl Esters	Omega-3 Acid Ethyl Esters	12	suppressed
Solifenacin Succinate	Solifenacin Succinate	12	suppressed
Spironolactone-Hctz	Spironolact/Hydrochlorothiazid	12	suppressed
Anoro Ellipta	Umeclidinium Brm/Vilanterol Tr	11	suppressed
Bupropion Hcl Sr	Bupropion Hcl	11	suppressed
Diltiazem 24hr Er	Diltiazem Hcl	11	suppressed
Estradiol	Estradiol	11	suppressed
Irbesartan	Irbesartan	11	suppressed
Methotrexate	Methotrexate Sodium	11	suppressed
Pentoxifylline	Pentoxifylline	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