Healthcare provider profile · identity verified

Mark S O'Brien, MD

Family Practice · CARMEL, IN · NPI 1124129267

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 Calcium686185
Amlodipine BesylateAmlodipine Besylate355101
Losartan PotassiumLosartan Potassium26273
LisinoprilLisinopril23363
Metoprolol SuccinateMetoprolol Succinate22158
Levothyroxine SodiumLevothyroxine Sodium20553
Metformin Hcl ErMetformin Hcl19555
HydrochlorothiazideHydrochlorothiazide17352
Tamsulosin HclTamsulosin Hcl16049
ValsartanValsartan14244
OmeprazoleOmeprazole12837
EzetimibeEzetimibe11028
Rosuvastatin CalciumRosuvastatin Calcium9929
SpironolactoneSpironolactone8026
GabapentinGabapentin7721
Potassium ChloridePotassium Chloride7725
FinasterideFinasteride7619
Triamterene-HydrochlorothiazidTriamterene/Hydrochlorothiazid7220
Lisinopril-HydrochlorothiazideLisinopril/Hydrochlorothiazide6821
MounjaroTirzepatide66suppressed
AllopurinolAllopurinol6217
EliquisApixaban5912
Pantoprazole SodiumPantoprazole Sodium5917
FurosemideFurosemide5716
MeloxicamMeloxicam5518
Fluoxetine HclFluoxetine Hcl5315
Metformin HclMetformin Hcl5316
Pravastatin SodiumPravastatin Sodium4812
Metoprolol TartrateMetoprolol Tartrate4615
Losartan-HydrochlorothiazideLosartan/Hydrochlorothiazide4514
PregabalinPregabalin44suppressed
Sertraline HclSertraline Hcl4111
ClopidogrelClopidogrel Bisulfate40suppressed
Glipizide ErGlipizide4011
Olmesartan MedoxomilOlmesartan Medoxomil4012
JardianceEmpagliflozin39suppressed
Montelukast SodiumMontelukast Sodium3911
SimvastatinSimvastatin3912
Albuterol Sulfate HfaAlbuterol Sulfate3816
Hydrocodone-AcetaminophenHydrocodone/Acetaminophen38suppressed
PrednisonePrednisone3830
Escitalopram OxalateEscitalopram Oxalate3713
CarvedilolCarvedilol3613
Bupropion XlBupropion Hcl30suppressed
Alendronate SodiumAlendronate Sodium27suppressed
Pioglitazone HclPioglitazone Hcl27suppressed
Trazodone HclTrazodone Hcl26suppressed
AlprazolamAlprazolam25suppressed
AtenololAtenolol25suppressed
Benazepril HclBenazepril Hcl24suppressed
Citalopram HbrCitalopram Hydrobromide23suppressed
Donepezil HclDonepezil Hcl23suppressed
Duloxetine HclDuloxetine Hcl23suppressed
FamotidineFamotidine23suppressed
Valsartan-HydrochlorothiazideValsartan/Hydrochlorothiazide23suppressed
Breo ElliptaFluticasone/Vilanterol22suppressed
CephalexinCephalexin2220
Diltiazem 24hr Er (Cd)Diltiazem Hcl22suppressed
FenofibrateFenofibrate22suppressed
Fluticasone PropionateFluticasone Propionate20suppressed
MyrbetriqMirabegron20suppressed
TrulicityDulaglutide20suppressed
Amlodipine Besylate-BenazeprilAmlodipine Besylate/Benazepril18suppressed
Fluticasone-SalmeterolFluticasone Propion/Salmeterol18suppressed
SynthroidLevothyroxine Sodium18suppressed
Terazosin HclTerazosin Hcl18suppressed
TorsemideTorsemide16suppressed
Cyclobenzaprine HclCyclobenzaprine Hcl15suppressed
ValacyclovirValacyclovir Hcl15suppressed
AcyclovirAcyclovir14suppressed
CelecoxibCelecoxib14suppressed
Nano 2nd Gen Pen NeedlePen Needle, Diabetic14suppressed
Oxybutynin Chloride ErOxybutynin Chloride14suppressed
TradjentaLinagliptin14suppressed
Trelegy ElliptaFluticasone/Umeclidin/Vilanter14suppressed
GlimepirideGlimepiride12suppressed
Lantus SolostarInsulin Glargine,hum.Rec.Anlog12suppressed
LovastatinLovastatin12suppressed
MirtazapineMirtazapine12suppressed
Propranolol HclPropranolol Hcl12suppressed
Propranolol Hcl ErPropranolol Hcl12suppressed
Buspirone HclBuspirone Hcl11suppressed
GlipizideGlipizide11suppressed
Paroxetine HclParoxetine Hcl11suppressed
Triamcinolone AcetonideTriamcinolone Acetonide11suppressed
Warfarin SodiumWarfarin Sodium11suppressed
Wixela InhubFluticasone Propion/Salmeterol11suppressed
XareltoRivaroxaban11suppressed

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