Jonathan Blair Williamson, M.D.
Gastroenterology Physician · Hartford, CT
Jonathan Blair Williamson, M.D. is a gastroenterology physician with a practice address in Hartford, Connecticut, and NPI 1881891703, issued on Jul 3, 2007. Check the license (Connecticut 052966, as entered in NPPES) on the Connecticut Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Jonathan Blair Williamson
- Credential
- M.D.
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License number
- 052966 CT
Self-reported in NPPES; status is on the state search - Practice location
- 85 Seymour St, Hartford, CT 06106
- Phone
- (860) 246-2571
- Enumerated
- Jul 3, 2007
- Record last updated
- Jan 4, 2019 (not updated in 7 years: call before relying on the address or phone)
- Fax
- (860) 246-3691
- Medicaid ID
- 008052313 CT
- Medicare enrollment
- Enrolled (PECOS I20140805001102); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 336 in Connecticut → Look up another NPI →
Also registered at 85 Seymour St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Jonathan Blair Williamson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersConnecticut Medical Examining Board
Search for license 052966Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
4% fewer Medicare Part D claims than the average gastroenterology physician in 2024
777 Medicare Part D claims for 287 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 16% of claims.
Most prescribed
- Omeprazole175 claims
- Pantoprazole Sodium143 claims
- Sod Sulf-Potass Sulf-Mag Sulf106 claims
- Lubiprostone41 claims
- Linzess36 claims
- Sucralfate36 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): 85.1 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).
Industry payments in 2024: $1,914.11
81 payments; by number, the most common kind was food and beverage; the largest payer was Abbvie Inc. The 13,350 providers of this specialty with any payment received $5,015.95 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through 2 group practices
- Connecticut GI PLLCHartford, CT
- Hartford Healthcare Medical Group Specialists PLLCBloomfield, CT
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Jonathan Blair Williamson among 336 gastroenterology physician records in Connecticut
Jonathan Blair Williamson, M.D. 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 2007, is newer than 51% of them.
- NPI issued2007 · 51% of these records are older, 36% newer
- In a Medicare fileYes · 86% of these records are
- In the CMS Doctors and Clinicians fileYes · 76% of these records are
- Graduated2007 · median 2001 among the 255 with a school on file
- Record last updated2019 · 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 Hartford → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- David Chaletsky, MDHartford, CT 061061316193055
- Teresa Da Cunha, MDHartford, CT 061061346806841
- Michael Einstein, M.D.Hartford, CT 061061659339901
- Michael Golioto, MDHartford, CT 061061811091432
- Maria Johnson, M.D.Hartford, CT 061061033300728
- Michael Karasik, MDHartford, CT 061061346344967
- Kristin Marcous, PAHartford, CT 061061801015854
- Jeffry Nestler, MDHartford, CT 061061275637886
Common questions
What is Jonathan Blair Williamson, M.D.'s NPI number?
Jonathan Blair Williamson, M.D.'s National Provider Identifier (NPI) is 1881891703, issued on Jul 3, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Jonathan Blair Williamson, M.D. located?
The NPPES record lists a practice address at 85 Seymour St, Hartford, CT, 06106. Phone: (860) 246-2571. Providers update this record themselves, so call before visiting.
How can I verify Jonathan Blair Williamson, M.D.'s license?
NPPES lists Connecticut license number 052966, 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 Jonathan Blair Williamson, M.D. prescribe under Medicare Part D?
In 2024, Jonathan Blair Williamson, M.D. had 777 Medicare Part D claims for 287 beneficiaries; the average among gastroenterology physician prescribers was 811. Part D covers Medicare prescriptions only.
What is Jonathan Blair Williamson, M.D.'s MIPS final score?
The 2023 MIPS final score is 85.1 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.