Healthcare provider profile · identity verified

Mary C O'Brien, M.D.

Internal Medicine · SHREWSBURY, MA · NPI 1912980434

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 Calcium387105
Losartan PotassiumLosartan Potassium23068
Rosuvastatin CalciumRosuvastatin Calcium21357
Levothyroxine SodiumLevothyroxine Sodium17443
LisinoprilLisinopril16948
LorazepamLorazepam13641
Metoprolol SuccinateMetoprolol Succinate11528
Sertraline HclSertraline Hcl11028
Alendronate SodiumAlendronate Sodium10933
HydrochlorothiazideHydrochlorothiazide10431
OmeprazoleOmeprazole9132
EliquisApixaban8917
Escitalopram OxalateEscitalopram Oxalate7621
EzetimibeEzetimibe7423
Oxycodone HclOxycodone Hcl7120
Amlodipine BesylateAmlodipine Besylate6922
Albuterol Sulfate HfaAlbuterol Sulfate6821
FurosemideFurosemide6221
SimvastatinSimvastatin6216
ClonazepamClonazepam5311
Pantoprazole SodiumPantoprazole Sodium5315
AtenololAtenolol5111
SynthroidLevothyroxine Sodium5114
Diltiazem 24hr Er (Cd)Diltiazem Hcl4715
Fluticasone PropionateFluticasone Propionate4714
FamotidineFamotidine44suppressed
Trazodone HclTrazodone Hcl4414
Duloxetine HclDuloxetine Hcl39suppressed
PrednisonePrednisone3913
GabapentinGabapentin35suppressed
Zolpidem TartrateZolpidem Tartrate34suppressed
AllopurinolAllopurinol29suppressed
Amitriptyline HclAmitriptyline Hcl28suppressed
Nitrofurantoin Mono-MacroNitrofurantoin Monohyd/M-Cryst2824
Citalopram HbrCitalopram Hydrobromide27suppressed
Metformin HclMetformin Hcl25suppressed
Montelukast SodiumMontelukast Sodium25suppressed
Tamsulosin HclTamsulosin Hcl25suppressed
TopiramateTopiramate25suppressed
Memantine HclMemantine Hcl24suppressed
ValacyclovirValacyclovir Hcl2412
EstradiolEstradiol23suppressed
IrbesartanIrbesartan23suppressed
Tramadol HclTramadol Hcl2313
Metformin Hcl ErMetformin Hcl22suppressed
ValsartanValsartan22suppressed
Amoxicillin-Clavulanate PotassAmoxicillin/Potassium Clav2015
Fluoxetine HclFluoxetine Hcl20suppressed
Meclizine HclMeclizine Hcl20suppressed
Venlafaxine Hcl ErVenlafaxine Hcl20suppressed
Azelastine HclAzelastine Hcl19suppressed
LovastatinLovastatin19suppressed
Sumatriptan SuccinateSumatriptan Succinate19suppressed
Butalbital-Acetaminophen-CaffeButalb/Acetaminophen/Caffeine16suppressed
Ondansetron HclOndansetron Hcl16suppressed
Oxybutynin Chloride ErOxybutynin Chloride16suppressed
OzempicSemaglutide16suppressed
Quetiapine FumarateQuetiapine Fumarate16suppressed
Hydrocodone-AcetaminophenHydrocodone/Acetaminophen15suppressed
Ipratropium BromideIpratropium Bromide15suppressed
MeloxicamMeloxicam15suppressed
IbuprofenIbuprofen14suppressed
TorsemideTorsemide14suppressed
AmoxicillinAmoxicillin13suppressed
Breo ElliptaFluticasone/Vilanterol13suppressed
Dicyclomine HclDicyclomine Hcl13suppressed
MirtazapineMirtazapine13suppressed
Ondansetron OdtOndansetron13suppressed
TrulicityDulaglutide13suppressed
Ventolin HfaAlbuterol Sulfate13suppressed
Doxycycline HyclateDoxycycline Hyclate12suppressed
Hydralazine HclHydralazine Hcl12suppressed
Sulfamethoxazole-TrimethoprimSulfamethoxazole/Trimethoprim12suppressed
AripiprazoleAripiprazole11suppressed
Propranolol Hcl ErPropranolol Hcl11suppressed
Wixela InhubFluticasone Propion/Salmeterol11suppressed

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