Doctor profile · Federal record

Dr. Margaret Callahan, MD

Medical Oncology Physician (CMS: Hematology/Oncology) · Medical Oncology Physician · Farmington, CT

  • NPI 1508098534
  • Accepts Medicare
  • MIPS 79.4 / 100 · 2023
  • 19 yrs in practice
  • Licensed in 2 states
  • Female
  • Group practice
  • No sanctions

Practice & contact

Operates at 2 locations .

NPPES Updated May 11, 2026
Primary practice
263 Farmington Ave
Farmington, CT 06030
(860) 679-2100
Additional location
1275 York Ave
New York, NY 100656007
(800) 585-4118

Credentials & registration

NPPES · NUCC
NPI registered
August 2009 — 17 yrs on file
Profile last updated
January 16, 2024
Year of graduation
2007 — 19 yrs since
Specialty taxonomy
207RX0202X — NUCC code
State licenses (2)
Connecticut #075986 · New York #251318-1

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1508098534. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
254
Distinct HCPCS
3
Medicare allowed
$23,672
HCPCS Description Services Patients Avg allowed
99214 Established patient office or other outpatient visit, 30-39 minutes 151 72 $109
99213 Established patient office or other outpatient visit, 20-29 minutes 89 60 $74
99212 Established patient office or other outpatient visit, 10-19 minutes 14 13 $40

In context: peer comparison

Among 2 peers in this city , average services per provider: 78. This provider delivers 3.3× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$4,325
Transactions
2
Manufacturers
2
Payer (manufacturer) Industry Txns Amount
Regeneron Pharmaceuticals, Inc. 1 $3,275.00
AstraZeneca AB 1 $1,050.00

By nature of payment

Consulting Fee
$4,325

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
26
Patients
0
Total drug cost
$162,700
Drug Type Claims Patients Total cost
Triamcinolone Acetonide Generic 15 0 $305
Mekinist (Trametinib Dimethyl Sulfoxide) Brand 11 0 $162,395

Frequently asked questions

Auto-generated from federal data
What is Dr. Margaret Callahan's medical specialty?
Dr. Margaret Callahan practices Medical Oncology Physician in Farmington, CT.
Where does Dr. Margaret Callahan practice?
Dr. Margaret Callahan practices at 263 Farmington Ave, Farmington, CT 06030. Office phone: 8606792100.
What is Dr. Margaret Callahan's NPI?
Dr. Margaret Callahan's National Provider Identifier (NPI) is 1508098534, issued by NPPES.
Does Dr. Margaret Callahan accept Medicare assignment?
Yes. Dr. Margaret Callahan accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Margaret Callahan commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); Established patient office or other outpatient visit (HCPCS 99213); Established patient office or other outpatient visit (HCPCS 99212). Source: CMS Medicare Physician & Other Practitioners file.