Has Margaret Callahan, MD received payments from drug or device companies?

Yes. Drug and device makers reported $33,178 in general payments to Margaret Callahan, MD across 29 transactions between 2019–2025. Most Open Payments records nationally are meals worth under $20; a reported payment is not evidence of wrongdoing.

Does a payment mean Margaret Callahan, MD did something wrong?

No. Federal law requires drug and device makers to report almost every transfer of value to a physician, including a $14 sandwich at a lunch presentation. Consulting fees, research funding and royalties to device inventors are ordinary, legal parts of medicine. This site reports what was disclosed; it makes no allegation.

Where does this information about Margaret Callahan, MD come from?

The U.S. Centers for Medicare & Medicaid Services. Payments come from Open Payments, published under the Physician Payments Sunshine Act. Billing and prescribing figures come from the Medicare Physician & Other Practitioners and Part D Prescriber public use files for 2024.

Margaret Callahan, MD

Medical Oncology · Farmington, CTNPI 1508098534

Payments from drug & device makers

What this record shows

This record is dominated by consulting fees: $31,694 of the $33,178 with a category attached, or 95.5%. 9 manufacturers reported payments, led by Astrazeneca AB at 32.7% of the total. Reporting peaked in 2023 at $12,088 and has fallen 64.2% since, to $4,325 in 2024.

$33,178in general payments, 2019–2025

Across 29 payments — averaging $1144.08 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.

Astrazeneca AB$11K
E.r. Squibb & Sons, L.L.C.$6K
Bayer$5K
Regeneron$3K
Immunocore Limited$3K
Daiichi Sankyo Inc.$2K
plus $3K from 3 others

$442,816in research payments, 2019–2025

Across 9 payments — averaging $49,202 each. Payments tied to a research study. These frequently flow through the physician to a hospital or research institution rather than to the physician personally.

AstraZeneca$382K
Genentech, Inc.$61K

What the payments were for

Consulting fees$31,69496%
Travel & lodging$8833%
Food & beverage$6022%

General payments by program year

Who reported the general payments

Companies are grouped under their corporate parent — a single manufacturer often files under several CMS reporting entities. Research and ownership payments are counted separately and are not in this table.

Company	Payments	Total
Astrazeneca AB	8	$10,850
E.r. Squibb & Sons, L.L.C.	10	$6,151
Bayer	2	$4,560
Regeneron	3	$3,476
Immunocore Limited	2	$3,342
Daiichi Sankyo Inc.	1	$1,875
AstraZeneca	1	$1,400
Acerta Pharma LLC	1	$1,400
Incyte Corporation	1	$123

What the payments were tied to

Products named in the reported payments. Only payments of $100 or more are attributed here — the typical reported payment nationally is a meal worth about $16, and listing those product-by-product would be noise.

IMFINZI$13,650
Non-Covered$4,560
KIMMTRAK$3,342
PEMAZYRE$123

How this compares

$33,178 in reported general payments places this provider in the 70th percentile of 79 medical oncology providers in Connecticut.

See all medical oncology providers in Connecticut →

Medicare billing

Part B allowed, 2024

$1,755

Medicare patients

Services billed

What this is not: this is the amount Original Medicare Part B allowed for services this provider billed in 2024. It is not their income. It excludes Medicare Advantage — now more than half of all Medicare enrollment — along with Medicaid and all commercial insurance, and it is gross practice revenue before staff, rent, supplies and malpractice premiums. CMS also suppresses any figure covering ten or fewer patients, so low-volume providers appear smaller than they are.

Other medical oncology in Farmington

Ana Acuna-VillaordunaFarmington$193
Peter MarksNew Haven$578K
Daniel PetrylakNew Haven$446K
Mandar MuzumdarNew Haven$371K
Barbara BurtnessNew Haven$297K
Ian KropNew Haven$219K
Joseph McLaughlinManchester$200K
Francine FossNew Haven$193K
William OhGreenwich$162K
Anne ChiangNew Haven$158K

See the full list for Connecticut →

Where these figures come from

Payments: CMS Open Payments, program years 2019–2025 (publication P06302026_06032026).
Billing: Medicare Physician & Other Practitioners, data year 2024. Original Medicare Part B only.
Identity: NPPES NPI Registry, July 2026.

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