Gregory Aaron Breuer, MD, PHD
Hematology & Oncology Physician · New Haven, CT
Gregory Aaron Breuer, MD, PHD is a hematology & oncology physician with a practice address in New Haven, Connecticut, and NPI 1629652417, issued on May 8, 2021. Check the license (Connecticut 1.076379, as entered in NPPES) on the Connecticut Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Gregory Aaron Breuer
- Credential
- MD, PHD
- Primary taxonomy
- Hematology & Oncology Physician 207RH0003X
- License number
- 1.076379 CT
Self-reported in NPPES; status is on the state search - Practice location
- 20 York St, New Haven, CT 06510
- Phone
- (203) 688-4242
- Enumerated
- May 8, 2021
- Record last updated
- Sep 16, 2024
- Entity
- Type 1 · individual
8 nearest hematology & oncology physician records → All 198 in Connecticut → Look up another NPI →
Also registered at 20 York St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Cyrena Abbasi, MDStudent in an Organized Health Care Education/Training Program1609703289
- Ali Abboud, MD, MBAStudent in an Organized Health Care Education/Training Program1942943097
- Basil Abdalla, MDStudent in an Organized Health Care Education/Training Program1154905057
- Jasmina AbdallaStudent in an Organized Health Care Education/Training Program1700638590
- Sarah AbdallahPsychiatry Physician1740800952
- Usama Abdelghany, PHARM DOncology Pharmacist1548827843
Verify Gregory Aaron Breuer in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersConnecticut Medical Examining Board
Search for license 1.076379Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
98% fewer Medicare Part D claims than the average hematology & oncology physician in 2024
15 Medicare Part D claims, against an average of 877 among the 10,784 providers of this specialty who prescribed in Part D.
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.
Gregory Aaron Breuer among 198 hematology & oncology physician records in Connecticut
Gregory Aaron Breuer, MD, PHD is one of 198 hematology & oncology physician records with a practice address in Connecticut. 77% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2021, is newer than 98% of them.
- NPI issued2021 · 98% of these records are older, 2% newer
- In a Medicare fileYes · 77% of these records are
- In the CMS Doctors and Clinicians fileNo · 70% of these records are
- Record last updated2024 · 67% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RH0003X and a Connecticut practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Hematology & Oncology Physician providers in Connecticut
There are 198 hematology & oncology physician records in Connecticut.
All 198 in Connecticut → Every provider in New Haven → Hematology & Oncology Physician nationwide →
The 8 hematology & oncology physician records with the nearest ZIP codes
- Prajwal Boddu, M.D.New Haven, CT 065101205178621
- Michael Cecchini, MDNew Haven, CT 065101184999336
- Emily Collier, MDNew Haven, CT 065101295963387
- Erin Hofstatter, M.D.New Haven, CT 065101467484998
- Scott Huntington, M.D.New Haven, CT 065101982847588
- Iris Isufi, M.D.New Haven, CT 065101407021140
- Arthur Levy, MDNew Haven, CT 065101043251135
- Jyoti Malhotra, M.D, MPHNew Haven, CT 065101598932170
Common questions
What is Gregory Aaron Breuer, MD, PHD's NPI number?
Gregory Aaron Breuer, MD, PHD's National Provider Identifier (NPI) is 1629652417, issued on May 8, 2021. An NPI identifies a provider in billing; it is not a license.
Where is Gregory Aaron Breuer, MD, PHD located?
The NPPES record lists a practice address at 20 York St, New Haven, CT, 06510. Phone: (203) 688-4242. Providers update this record themselves, so call before visiting.
How can I verify Gregory Aaron Breuer, MD, PHD's license?
NPPES lists Connecticut license number 1.076379, 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 Aaron Breuer, MD, PHD prescribe under Medicare Part D?
In 2024, Gregory Aaron Breuer, MD, PHD had 15 Medicare Part D claims; the average among hematology & oncology physician prescribers was 877. Part D covers Medicare prescriptions only.
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.