What is Daniel O'brien's specialty?

Daniel O'brien (NPI 1518132505) is a Medicare-billing provider whose primary specialty is Gastroenterology in Danbury, CT.

Where does Daniel O'brien practice?

Daniel O'brien practices in Danbury, CT, based on the location reported in the CMS Medicare provider datasets for NPI 1518132505.

How much does Medicare pay Daniel O'brien?

Daniel O'brien (NPI 1518132505) received approximately $53K in total Medicare Part B payments, serving 198 beneficiaries, per the CMS Medicare Physician & Other Practitioners dataset.

PROVIDER PROFILE · NPI 1518132505

Daniel O'brienM.D.

GastroenterologyDanbury, CTI

MEDICARE UTILIZATION · PART B · 2024

Total beneficiaries

281

Unique beneficiaries

—

Total services

325

Distinct HCPCS

Medicare payment

$36K

Peer benchmark

Total Medicare services vs. 260 Gastroenterology providers in CT — below median (cohort median 519).

PRESCRIBING · PART D · 2024

Total Rx claims

380

Beneficiaries

—

Total drug cost

$18K

Distinct drugs

Brand share

17.9%

Top prescribed drugs

Pantoprazole Sodium181 claims

Peg3350/Sod Sulf,bicarb,cl/Kcl57 claims

Omeprazole54 claims

Famotidine53 claims

Esomeprazole Magnesium24 claims

QUALITY · MIPS · 2024

No data available for this provider in 2024.

INDUSTRY PAYMENTS · OPEN PAYMENTS · 2025

No data available for this provider in 2025.

REFERRAL NETWORK

Where Daniel O'brien's patients come from & go

Directional shared-patient flow from Medicare claims — who sends patients to this provider (inbound) and where this provider's patients go next (outbound). 51 inbound referrers · 0 outbound destinations.

Receives referrals from

Inbound — who sends patients here

Physician	Patients	Visits
Marvin Prince Gastroenterology · Danbury, CT	113	199
Adam Welber Diagnostic Radiology · Danbury, CT	53	87
Michael Logue Cardiology · Bridgeport, CT	51	86
Jeffrey Schmierer Cardiology · Danbury, CT	50	86
KELLER, ANDREW	41	64
Thorsten Krebs Diagnostic Radiology · Danbury, CT	30	58
Quest Diagnostics Llc Clinical Laboratory · Wallingford, CT	30	116
Jessica Dodge Pathology · Danbury, CT	29	50
Seema Bakhru Diagnostic Radiology · Hartford, CT	28	41
Mohamed Ahmed Internal Medicine · Danbury, CT	28	120
Janaka Periyapperuma Internal Medicine · Danbury, CT	28	110
Todd Everett Diagnostic Radiology · Danbury, CT	28	46

Refers patients to

Outbound — where patients go next

No outbound pairs above the suppression threshold.

Source: CMS Physician Shared Patient Patterns (30-day window, Medicare FFS). Direction = a beneficiary seen by the first provider, then the second, within 30 days; a proxy for referral, not a documented referral. Pairs with fewer than 11 shared beneficiaries are suppressed.

CROSS-REFERENCE

Related data on other Healthparse brands

ProviderScore

OIG/SAM exclusion screening, sanctions history

Healthparse Signals

Monitor this provider for changes — dated NPI change events