Healthcare provider profile · identity verified

Mark Leonard Herring, M.D.

Internal Medicine · MANITOWOC, WI · NPI 1386766368

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
Levothyroxine SodiumLevothyroxine Sodium19233
Losartan PotassiumLosartan Potassium17029
Atorvastatin CalciumAtorvastatin Calcium15433
SimvastatinSimvastatin15131
Warfarin SodiumWarfarin Sodium14619
FurosemideFurosemide14435
Amlodipine BesylateAmlodipine Besylate13024
Metoprolol SuccinateMetoprolol Succinate11927
LisinoprilLisinopril11229
Pantoprazole SodiumPantoprazole Sodium10921
ClopidogrelClopidogrel Bisulfate10517
Hydrocodone-AcetaminophenHydrocodone/Acetaminophen10227
OmeprazoleOmeprazole9220
Citalopram HbrCitalopram Hydrobromide7711
Metoprolol TartrateMetoprolol Tartrate7219
HydrochlorothiazideHydrochlorothiazide7120
MirtazapineMirtazapine6713
Pramipexole DihydrochloridePramipexole Di-Hcl67suppressed
Enalapril MaleateEnalapril Maleate5513
AllopurinolAllopurinol5414
Escitalopram OxalateEscitalopram Oxalate53suppressed
Metformin Hcl ErMetformin Hcl5314
Tramadol HclTramadol Hcl52suppressed
FinasterideFinasteride5112
LorazepamLorazepam4814
Tamsulosin HclTamsulosin Hcl48suppressed
Rosuvastatin CalciumRosuvastatin Calcium4713
EliquisApixaban36suppressed
Fluticasone-SalmeterolFluticasone Propion/Salmeterol35suppressed
FentanylFentanyl34suppressed
Doxazosin MesylateDoxazosin Mesylate33suppressed
AtenololAtenolol32suppressed
PrednisonePrednisone32suppressed
CarvedilolCarvedilol31suppressed
Trazodone HclTrazodone Hcl28suppressed
ValsartanValsartan27suppressed
GabapentinGabapentin26suppressed
Zolpidem TartrateZolpidem Tartrate26suppressed
Albuterol Sulfate HfaAlbuterol Sulfate23suppressed
DigoxinDigoxin22suppressed
GlimepirideGlimepiride21suppressed
Triamterene-HydrochlorothiazidTriamterene/Hydrochlorothiazid21suppressed
Carbidopa-LevodopaCarbidopa/Levodopa20suppressed
Nebivolol HclNebivolol Hcl20suppressed
Diltiazem 24hr Er (Cd)Diltiazem Hcl19suppressed
Duloxetine HclDuloxetine Hcl19suppressed
LevetiracetamLevetiracetam19suppressed
Metformin HclMetformin Hcl19suppressed
SynthroidLevothyroxine Sodium19suppressed
Dilt-XrDiltiazem Hcl18suppressed
Lantus SolostarInsulin Glargine,hum.Rec.Anlog18suppressed
Divalproex SodiumDivalproex Sodium17suppressed
Novolog FlexpenInsulin Aspart17suppressed
Quetiapine FumarateQuetiapine Fumarate17suppressed
AripiprazoleAripiprazole16suppressed
Fluticasone PropionateFluticasone Propionate16suppressed
FamotidineFamotidine14suppressed
Lisinopril-HydrochlorothiazideLisinopril/Hydrochlorothiazide14suppressed
Oxybutynin Chloride ErOxybutynin Chloride14suppressed
AmoxicillinAmoxicillin13suppressed
Arnuity ElliptaFluticasone Furoate13suppressed
Basaglar Kwikpen U-100Insulin Glargine,hum.Rec.Anlog13suppressed
Donepezil HclDonepezil Hcl13suppressed
SpironolactoneSpironolactone13suppressed
Breo ElliptaFluticasone/Vilanterol12suppressed
CephalexinCephalexin12suppressed
Ciprofloxacin HclCiprofloxacin Hcl1211
Isosorbide Mononitrate ErIsosorbide Mononitrate12suppressed
Metoclopramide HclMetoclopramide Hcl12suppressed
BumetanideBumetanide11suppressed
Fiasp FlextouchInsulin Aspart (Niacinamide)11suppressed
MesalamineMesalamine11suppressed
Sertraline HclSertraline Hcl11suppressed

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