Healthcare provider profile · identity verified

Shannon E O'Mahar, MD

Allopathic & Osteopathic Physicians|Internal Medicine|Hematology & Oncology · MADISON, WI · NPI 1366569899

Profile state: payments and partd 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

CMS Open Payments records show Shannon E O'Mahar, MD received $115.34 in general payments during 2025 across 1 reported records.

Tempus AI, Inc accounted for 100.0% of that reported general-payment amount.

The Open Payments records used for this analysis explicitly named 1 associated product.

These records do not establish that a payment influenced prescribing or medical care.

Payment overview · 2025

General Payments

$115.34

1 reported records · 1 companies

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.

Who paid this doctor?

Companies in 2025 General Payments

Reported companyCanonical companyAmountShareRecordsYear
Tempus AI, Inc Unresolved — no canonical attribution shown $115.34100.0%12025

What were the payments for?

Payment categories

CategoryAmountRecords
Food and Beverage$115.341

A meal, consulting fee, royalty, and travel payment describe different kinds of reported relationships and should not be interpreted as equivalent.

Analysis 1 · Payment-linked products

Products named in Open Payments records

Reported productTypeReported companyRelated amount*RecordsYear
XT CDX
Normalized: xt cdx
Device Tempus AI, Inc $115.34 1 2025
Source payment records

* Product-associated amounts are non-additive because one payment record may name more than one product.

These products were named on specific Open Payments records. A named product does not show that the payment influenced treatment or prescribing.

Public prescribing for products named in payments

No exact normalized or approved-alias overlap was found in the loaded Part D year. This does not mean the doctor never prescribed the product.

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.

None of this doctor’s payer companies has same-entity product evidence that passes the publication threshold. The site does not infer company ownership, affiliates, or generic manufacturers.

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
AcyclovirAcyclovir29366
RevlimidLenalidomide21730
DexamethasoneDexamethasone15746
HydroxyureaHydroxyurea15637
AnastrozoleAnastrozole12038
PrednisonePrednisone11727
PomalystPomalidomide9818
Tamoxifen CitrateTamoxifen Citrate8721
Potassium ChloridePotassium Chloride7828
Imatinib MesylateImatinib Mesylate65suppressed
BrukinsaZanubrutinib58suppressed
Abiraterone AcetateAbiraterone Acetate52suppressed
LetrozoleLetrozole5011
Prochlorperazine MaleateProchlorperazine Maleate4932
VenclextaVenetoclax48suppressed
LenalidomideLenalidomide42suppressed
CalquenceAcalabrutinib Maleate39suppressed
Ondansetron HclOndansetron Hcl3934
Oxycodone HclOxycodone Hcl3914
EliquisApixaban38suppressed
AllopurinolAllopurinol3614
ImbruvicaIbrutinib32suppressed
SprycelDasatinib32suppressed
JakafiRuxolitinib Phosphate30suppressed
LorazepamLorazepam27suppressed
VoriconazoleVoriconazole27suppressed
OmeprazoleOmeprazole24suppressed
Hydrocodone-AcetaminophenHydrocodone/Acetaminophen23suppressed
LevofloxacinLevofloxacin23suppressed
Sulfamethoxazole-TrimethoprimSulfamethoxazole/Trimethoprim23suppressed
FurosemideFurosemide20suppressed
CholestyramineCholestyramine (With Sugar)19suppressed
Morphine Sulfate ErMorphine Sulfate19suppressed
InqoviDecitabine/Cedazuridine18suppressed
NinlaroIxazomib Citrate18suppressed
XtandiEnzalutamide18suppressed
ExemestaneExemestane17suppressed
IbrancePalbociclib15suppressed
MethotrexateMethotrexate Sodium14suppressed
AlprazolamAlprazolam13suppressed
Doxycycline HyclateDoxycycline Hyclate13suppressed
PromactaEltrombopag Olamine13suppressed
FamotidineFamotidine12suppressed
InrebicFedratinib Dihydrochloride12suppressed
Montelukast SodiumMontelukast Sodium12suppressed
OjjaaraMomelotinib Dihydrochloride12suppressed
TagrissoOsimertinib Mesylate12suppressed
Tramadol HclTramadol Hcl12suppressed
OlanzapineOlanzapine11suppressed

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 $115.34 · 1 records Tempus AI, Inc XT CDX
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