Gregory R. D'Onofrio, M.D.
Cardiovascular Disease Physician · Stamford, CT
Gregory R. D'Onofrio, M.D. is a cardiovascular disease physician with a practice address in Stamford, Connecticut, and NPI 1255304796, issued on Feb 7, 2006. Check the license (Connecticut 149608, as entered in NPPES) on the Connecticut Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Gregory R. D'Onofrio
- Credential
- M.D.
- Primary taxonomy
- Cardiovascular Disease Physician 207RC0000X
- License number
- 149608 CT
Self-reported in NPPES; status is on the state search - Practice location
- 29 Hospital Plaza, Stamford, CT 06902
- Phone
- (203) 348-7410
- Enumerated
- Feb 7, 2006
- Record last updated
- Sep 7, 2023
- Fax
- (203) 961-8488
- Medicare enrollment
- Enrolled (PECOS I20100916000299); accepts Medicare assignment
- Medical or professional school
- George Washington University School Of Medicine, 1967
- Entity
- Type 1 · individual
8 nearest cardiovascular disease physician records → All 503 in Connecticut → Look up another NPI →
Also registered at 29 Hospital Plaza
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Sarah Buckingham, MDNeurology Physician1447549639
- Salvatore Carbonaro, M.D.Cardiovascular Disease Physician1821141805
- Joonun Choi, MDCardiovascular Disease Physician1053583914
- Kathryn CreaghAdult Health Nurse Practitioner1588088355
- Evelyn Cusack, M.D.Cardiovascular Disease Physician1700874435
- Marissa Defreese, MDSurgical Critical Care Physician1194963462
Verify Gregory R. D'Onofrio in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersConnecticut Medical Examining Board
Search for license 149608Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
26% fewer Medicare Part D claims than the average cardiovascular disease physician in 2024
2,288 Medicare Part D claims for 296 beneficiaries, against an average of 3,078 among the 20,728 providers of this specialty who prescribed in Part D. Brand-name drugs were 14% of claims.
Most prescribed
- Metoprolol Succinate247 claims
- Amlodipine Besylate199 claims
- Atorvastatin Calcium193 claims
- Eliquis155 claims
- Losartan Potassium127 claims
- Furosemide123 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The practice group's MIPS final score for 2023 (Medicare payment program): 79.1 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Stamford Health Medical Group IncStamford, CT
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Gregory R. D'Onofrio among 503 cardiovascular disease physician records in Connecticut
Gregory R. D'Onofrio, M.D. is one of 503 cardiovascular disease physician records with a practice address in Connecticut. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 23% of them.
- NPI issued2006 · 23% of these records are older, 45% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 69% of these records are
- Graduated1967 · median 2000 among the 348 with a school on file
- Record last updated2023 · 71% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RC0000X and a Connecticut practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Cardiovascular Disease Physician providers in Connecticut
There are 503 cardiovascular disease physician records in Connecticut.
All 503 in Connecticut → Every provider in Stamford → Cardiovascular Disease Physician nationwide →
The 8 cardiovascular disease physician records with the nearest ZIP codes
- Ronald Aronson, M.D.Stamford, CT 069021285739763
- Ricardo Benenstein, MDStamford, CT 069021740470459
- Salvatore Carbonaro, M.D.Stamford, CT 069021821141805
- Joonun Choi, MDStamford, CT 069021053583914
- Evelyn Cusack, M.D.Stamford, CT 069021700874435
- Jeffrey Green, M.D.Stamford, CT 069021366415804
- Steven Horowitz, MDStamford, CT 069021427164953
- David Hsi, MDStamford, CT 069021588616312
Common questions
What is Gregory R. D'Onofrio, M.D.'s NPI number?
Gregory R. D'Onofrio, M.D.'s National Provider Identifier (NPI) is 1255304796, issued on Feb 7, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Gregory R. D'Onofrio, M.D. located?
The NPPES record lists a practice address at 29 Hospital Plaza, Stamford, CT, 06902. Phone: (203) 348-7410. Providers update this record themselves, so call before visiting.
How can I verify Gregory R. D'Onofrio, M.D.'s license?
NPPES lists Connecticut license number 149608, as entered by the provider. Search the Connecticut Medical Examining Board at https://www.elicense.ct.gov/Lookup/LicenseLookup.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Gregory R. D'Onofrio, M.D. prescribe under Medicare Part D?
In 2024, Gregory R. D'Onofrio, M.D. had 2,288 Medicare Part D claims for 296 beneficiaries; the average among cardiovascular disease physician prescribers was 3,078. Part D covers Medicare prescriptions only.
What is Gregory R. D'Onofrio, M.D.'s MIPS final score?
The 2023 MIPS final score is 79.1 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.