Are NPI numbers public?

Yes. NPI numbers are public federal identifiers in CMS NPPES. This page shows the public NPPES facts Fonteum has for NPI 1508098534: provider name, entity type, taxonomy, practice location, enumeration date, last-updated date, and source snapshot date. It does not include patient information.

What does the NPI record show for Margaret Callahan?

Margaret Callahan (NPI 1508098534) appears in CMS NPPES as oncologist in Farmington, CT. NPPES is administrative identity data submitted to CMS by providers and organizations; this page displays the source snapshot date as 2026-05-06.

Does this page assign a provider score?

No derived score is assigned on this provider page. NPPES is an identity registry; when a CMS QPP MIPS value is available, Fonteum displays that public CMS value with its source, and absence of a MIPS value is not a quality signal.

Does no exclusion match amount to a clearance?

Coverage is indeterminate, so this page makes no negative exclusion determination. This is not a clearance; check the current issuing-agency lists.

Where does the provider data come from?

The identity fields come from CMS NPPES. Additional sections appear only when a public source has a matching row, such as CMS PECOS, CMS Open Payments, Medicare Part D, CMS QPP MIPS, OIG LEIE, or state Medicaid exclusion lists. Source and date metadata appears where the response supplies it; unavailable dates are labeled.

Margaret Callahan — NPI 1508098534: exclusion

Name: Provider record — NPI 1508098534 (Margaret Callahan)
Creator: Fonteum
License: https://www.usa.gov/government-works

Built on the authoritative federal record

The primary sources, named on every page.

These are the federal agencies whose public datasets Fonteum ingests and attributes — the issuing authorities, not customers or partners. Every figure on the site links back to one of them.

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Source and date

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The platform records table row counts daily. Those observations detect local drift; they do not imply that an upstream publisher released or Fonteum ingested new data that day.

Named medical review

Reviewed by Jennifer Montecillo, MD, medical reviewer. Non-practicing medical reviewer.

Read the full provenance and attestation methodology →

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Margaret Callahan — NPI 1508098534: exclusion — Fonteum

Cross-source identity

Sources that publish this NPI

National Provider Identifier 1508098534 appears in the source rows shown below. Sources that do not publish NPI use their own identifiers and are not treated as deterministic NPI matches. Chips show response-supplied dates when available; otherwise they are labeled date unavailable.

NPPESOPEN PAYMENTS

Federal sources carrying NPI 1508098534
Federal source	Key	What it provides	Source & date
CMS NPPES	NPI 1508098534	Registry identity — oncologist, taxonomy 207RX0202X	Source:CMS NPPESSnapshot 2026-05-06
CMS Open Payments	NPI 1508098534	2 industry-payment records, 2024	Source:CMS Open PaymentsSnapshot PY2024

Industry payments

Open Payments received

Payments and transfers of value this clinician received from drug and device manufacturers, disclosed under the Physician Payments Sunshine Act. A payment is a disclosure, not a judgment.

$4,325

Total received

Payment records

Manufacturers

2024-03-04

Latest payment

Top categories

Largest payment categories by dollars
Nature of payment	Amount	Records
Consulting Fee	$4,325	2

Top manufacturers

Largest paying manufacturers by dollars
Manufacturer	Amount	Records
Regeneron Pharmaceuticals, Inc.	$3,275	1
Astrazeneca Ab	$1,050	1

Source:CMS Open PaymentsSnapshot PY2024National Open Payments analysis →

Ownership & affiliations

Who owns, operates, or is affiliated with this provider

Chain membership, ownership, and operating relationships from federal records — each one backed by a government source row. Most individual clinicians have none; owners and organizations carry more.

Ownership and affiliation records
Relationship	Entity	Source
← pays	Astrazeneca Ab	cms open payments
← pays	Regeneron Pharmaceuticals, Inc. (NY)	cms open payments

Full record card →Entity JSON

Margaret Callahan

Public NPPES answers

Are NPI numbers public?

What does the NPI record show for Margaret Callahan?

Does this page assign a provider score?

Does no exclusion match amount to a clearance?

Where does the provider data come from?

Sources that publish this NPI

Open Payments received

Top categories

Top manufacturers

MIPS quality score

Standing

Who owns, operates, or is affiliated with this provider

Retained versions for this record

Margaret Callahan

Public NPPES answers

Are NPI numbers public?

What does the NPI record show for Margaret Callahan?

Data-use and correction resources.

Does this page assign a provider score?

Does no exclusion match amount to a clearance?

Where does the provider data come from?

Sources that publish this NPI

Open Payments received

Top categories

Top manufacturers

MIPS quality score

Standing

Who owns, operates, or is affiliated with this provider

Retained versions for this record

Context for this record