Jonathan Williamson, M.D.
NPI 1881891703 · Gastroenterology Physician · Hartford, CT
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Jonathan Williamson, M.D. is a Gastroenterology Physician provider in Hartford, CT (NPI 1881891703).
Provider details
- NPI number
- 1881891703
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 052966 (CT)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
18 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
363 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 70 | $134 |
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 48 | $123 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 46 | $93 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 41 | $81 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 40 | $130 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 12 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Omeprazole | 175 | 61 |
| Pantoprazole Sodium | 143 | 41 |
| Sodium, Potassium,mag Sulfatesbrand: Sod Sulf-Potass Sulf-Mag Sulf | 106 | 101 |
| Lubiprostone | 41 | — |
| Sucralfate | 36 | 13 |
| Linaclotidebrand: Linzess | 36 | — |
| Famotidine | 33 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$1,914 across 81 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-07-03
- Last updated
- 2019-01-04
Frequently asked questions
- What is Jonathan Williamson's NPI number?
- Jonathan Williamson's National Provider Identifier (NPI) is 1881891703, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Jonathan Williamson's specialty?
- Jonathan Williamson is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Jonathan Williamson located?
- Jonathan Williamson's practice location on file with NPPES is 85 Seymour St, Hartford, CT 06106-5501.
- What is Jonathan Williamson's phone number?
- The practice phone number listed in the NPPES registry for Jonathan Williamson is (860) 246-2571.
- Does Jonathan Williamson accept Medicare?
- Jonathan Williamson is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Jonathan Williamson's NPI active?
- Yes — Jonathan Williamson's NPI (1881891703) is active in the NPPES registry as of the last update on 2019-01-04.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.