Michael Harris Nathanson, MD
Gastroenterology Physician · New Haven, CT
Michael Harris Nathanson, MD is a gastroenterology physician with a practice address in New Haven, Connecticut, and NPI 1437132230, issued on Nov 25, 2005. Check the license (Connecticut 029365, as entered in NPPES) on the Connecticut Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Michael Harris Nathanson
- Credential
- MD
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License numbers
- 029365 CT
ME158547 FL
Self-reported in NPPES; status is on the state search - Practice location
- 15 York St, New Haven, CT 06510
- Phone
- (203) 785-4138
- Enumerated
- Nov 25, 2005
- Record last updated
- Apr 2, 2026
- Fax
- (203) 737-1345
- Medicaid IDs
- 001293654 CT
129020000 FL - Medicare enrollment
- Enrolled (PECOS I20100503000382); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 336 in Connecticut → Look up another NPI →
Also registered at 15 York St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Nigel Bamford, MDNeurology with Special Qualifications in Child Neurology Physician1639255318
- Ami Belmont, M.D.Internal Medicine Physician1295183226
- Jean Bolognia, MDDermatology Physician1942291331
Verify Michael Harris Nathanson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersConnecticut Medical Examining Board
Search for license 029365Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
The practice group's MIPS final score for 2023 (Medicare payment program): 73.6 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
- Yale UniversityNew Haven, CT
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Michael Harris Nathanson among 336 gastroenterology physician records in Connecticut
Michael Harris Nathanson, MD is one of 336 gastroenterology physician records with a practice address in Connecticut. 86% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 85% newer
- In a Medicare fileYes · 86% of these records are
- In the CMS Doctors and Clinicians fileYes · 76% of these records are
- Graduated1985 · median 2001 among the 255 with a school on file
- Record last updated2026 · 69% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0100X and a Connecticut practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Gastroenterology Physician providers in Connecticut
There are 336 gastroenterology physician records in Connecticut.
All 336 in Connecticut → Every provider in New Haven → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- Harry Aslanian, MDNew Haven, CT 065101295718401
- Sidney Bogardus, MDNew Haven, CT 065101730131103
- James Boyer, M.D.New Haven, CT 065101447233267
- Samuel Feldshon, MDNew Haven, CT 065101861464547
- Rosemarie Fisher, MDNew Haven, CT 065101174507685
- Guadalupe Garcia Tsao, MDNew Haven, CT 065101194706416
- Wolfram Goessling, MD PHDNew Haven, CT 065101083696298
- Chul Hyun, MDNew Haven, CT 065101467540401
Common questions
What is Michael Harris Nathanson, MD's NPI number?
Michael Harris Nathanson, MD's National Provider Identifier (NPI) is 1437132230, issued on Nov 25, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Michael Harris Nathanson, MD located?
The NPPES record lists a practice address at 15 York St, New Haven, CT, 06510. Phone: (203) 785-4138. Providers update this record themselves, so call before visiting.
How can I verify Michael Harris Nathanson, MD's license?
NPPES lists Connecticut license number 029365, 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.
What is Michael Harris Nathanson, MD's MIPS final score?
The 2023 MIPS final score is 73.6 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.