Healthcare provider profile · identity verified

William J Riesen, MD

Internal Medicine · MASON CITY, IA · NPI 1548377997

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
Atorvastatin CalciumAtorvastatin Calcium435136
Levothyroxine SodiumLevothyroxine Sodium28370
LisinoprilLisinopril27072
Losartan PotassiumLosartan Potassium26672
OmeprazoleOmeprazole23368
EliquisApixaban22532
Metoprolol SuccinateMetoprolol Succinate22558
GabapentinGabapentin20850
HydrochlorothiazideHydrochlorothiazide16442
Tamsulosin HclTamsulosin Hcl16239
Amlodipine BesylateAmlodipine Besylate15340
Metformin HclMetformin Hcl14836
SimvastatinSimvastatin14541
FurosemideFurosemide14240
CarvedilolCarvedilol13831
Pantoprazole SodiumPantoprazole Sodium13630
Rosuvastatin CalciumRosuvastatin Calcium12034
Trazodone HclTrazodone Hcl10617
Fluoxetine HclFluoxetine Hcl9827
Potassium ChloridePotassium Chloride9821
ClopidogrelClopidogrel Bisulfate9320
Duloxetine HclDuloxetine Hcl9323
Tramadol HclTramadol Hcl8721
Albuterol Sulfate HfaAlbuterol Sulfate8620
SpironolactoneSpironolactone8016
Warfarin SodiumWarfarin Sodium8023
FamotidineFamotidine7418
Hydrocodone-AcetaminophenHydrocodone/Acetaminophen7313
Bupropion XlBupropion Hcl7024
AllopurinolAllopurinol6819
Escitalopram OxalateEscitalopram Oxalate6814
Donepezil HclDonepezil Hcl64suppressed
Metoprolol TartrateMetoprolol Tartrate6318
Fluticasone PropionateFluticasone Propionate6221
Pravastatin SodiumPravastatin Sodium6215
Montelukast SodiumMontelukast Sodium5919
Quetiapine FumarateQuetiapine Fumarate50suppressed
Buspirone HclBuspirone Hcl4711
TorsemideTorsemide4612
OzempicSemaglutide44suppressed
Sertraline HclSertraline Hcl4411
TopiramateTopiramate41suppressed
AlprazolamAlprazolam39suppressed
Zolpidem TartrateZolpidem Tartrate38suppressed
Citalopram HbrCitalopram Hydrobromide3711
Venlafaxine Hcl ErVenlafaxine Hcl37suppressed
AtenololAtenolol35suppressed
PrednisonePrednisone3514
Metformin Hcl ErMetformin Hcl3413
Alendronate SodiumAlendronate Sodium3312
MirtazapineMirtazapine32suppressed
Lisinopril-HydrochlorothiazideLisinopril/Hydrochlorothiazide3112
Paroxetine HclParoxetine Hcl31suppressed
JardianceEmpagliflozin30suppressed
Ipratropium-AlbuterolIpratropium/Albuterol Sulfate29suppressed
LamotrigineLamotrigine29suppressed
FenofibrateFenofibrate Nanocrystallized28suppressed
Arnuity ElliptaFluticasone Furoate27suppressed
Benazepril HclBenazepril Hcl27suppressed
Isosorbide Mononitrate ErIsosorbide Mononitrate27suppressed
TrulicityDulaglutide26suppressed
BaclofenBaclofen24suppressed
Cyclobenzaprine HclCyclobenzaprine Hcl23suppressed
LevetiracetamLevetiracetam21suppressed
Oxycodone HclOxycodone Hcl21suppressed
LorazepamLorazepam20suppressed
Memantine HclMemantine Hcl20suppressed
Oxybutynin ChlorideOxybutynin Chloride20suppressed
Propranolol HclPropranolol Hcl20suppressed
Ropinirole HclRopinirole Hcl20suppressed
Triamterene-HydrochlorothiazidTriamterene/Hydrochlorothiazid20suppressed
Ultra-Fine Short Pen NeedlePen Needle, Diabetic20suppressed
Hydralazine HclHydralazine Hcl18suppressed
Lantus SolostarInsulin Glargine,hum.Rec.Anlog18suppressed
Losartan-HydrochlorothiazideLosartan/Hydrochlorothiazide18suppressed
SynthroidLevothyroxine Sodium18suppressed
Amiodarone HclAmiodarone Hcl17suppressed
ClonazepamClonazepam17suppressed
FinasterideFinasteride17suppressed
Fluticasone-SalmeterolFluticasone Propion/Salmeterol17suppressed
Pramipexole DihydrochloridePramipexole Di-Hcl17suppressed
Trelegy ElliptaFluticasone/Umeclidin/Vilanter17suppressed
Diltiazem 24hr Er (Cd)Diltiazem Hcl16suppressed
Propranolol Hcl ErPropranolol Hcl16suppressed
Basaglar Kwikpen U-100Insulin Glargine,hum.Rec.Anlog15suppressed
Breo ElliptaFluticasone/Vilanterol15suppressed
Carbidopa-LevodopaCarbidopa/Levodopa15suppressed
Diltiazem 24hr ErDiltiazem Hcl15suppressed
LansoprazoleLansoprazole15suppressed
RybelsusSemaglutide15suppressed
Verapamil ErVerapamil Hcl15suppressed
Spiriva HandihalerTiotropium Bromide14suppressed
Spiriva RespimatTiotropium Bromide14suppressed
Ventolin HfaAlbuterol Sulfate14suppressed
ErythromycinErythromycin Base13suppressed
FenofibrateFenofibrate13suppressed
Levocetirizine DihydrochlorideLevocetirizine Dihydrochloride13suppressed
PrimidonePrimidone13suppressed
CephalexinCephalexin12suppressed
Dabigatran EtexilateDabigatran Etexilate Mesylate12suppressed
Incruse ElliptaUmeclidinium Bromide12suppressed
MethylprednisoloneMethylprednisolone12suppressed
Cinacalcet HclCinacalcet Hcl11suppressed
EpitolCarbamazepine11suppressed
EzetimibeEzetimibe11suppressed
FarxigaDapagliflozin Propanediol11suppressed
Hydroxychloroquine SulfateHydroxychloroquine Sulfate11suppressed
LovastatinLovastatin11suppressed
Timolol MaleateTimolol Maleate11suppressed
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