John Hennessey, M.D.
NPI 1215916564 · Internal Medicine Physician · Gales Ferry, CT
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Hennessey, M.D. is a Internal Medicine Physician provider in Gales Ferry, CT (NPI 1215916564).
Provider details
- NPI number
- 1215916564
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 037592 (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
20 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
5,116 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 1,485 | $133 |
| Urinalysis, Manual Test81002 | 451 | $3 |
| Routine Electrocardiogram (ecg) Using at Least 12 Leads With Interpretation and Report93000 | 443 | $15 |
| Subsequent Nursing Facility Care With Moderate Level of Medical Decision Making, Per Day, If Using Time, at Least 30 Minutes99309 | 442 | $111 |
| Blood Glucose (sugar) Test Performed By Hand-Held Instrument82962 | 437 | $3 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 205 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 1,306 | 323 |
| Amlodipine Besylate | 647 | 185 |
| Lisinopril | 610 | 167 |
| Levothyroxine Sodium | 493 | 112 |
| Apixabanbrand: Eliquis | 458 | 64 |
| Losartan Potassium | 420 | 107 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$1,517 across 59 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
- 2006-01-14
- Last updated
- 2012-11-30
Frequently asked questions
- What is John Hennessey's NPI number?
- John Hennessey's National Provider Identifier (NPI) is 1215916564, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Hennessey's specialty?
- John Hennessey is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is John Hennessey located?
- John Hennessey's practice location on file with NPPES is 1527 Route 12, Gales Ferry, CT 06335-1800.
- What is John Hennessey's phone number?
- The practice phone number listed in the NPPES registry for John Hennessey is (860) 464-7253.
- Does John Hennessey accept Medicare?
- John Hennessey is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Hennessey's NPI active?
- Yes — John Hennessey's NPI (1215916564) is active in the NPPES registry as of the last update on 2012-11-30.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.