Quick answers
- Does John Francis M. Hennecken accept Medicare assignment?
- Yes. Medicare's clinician data says John Francis M. Hennecken accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does John Francis M. Hennecken see?
- In 2024, CMS data shows 219 Original Medicare patients and 886 services for John Francis M. Hennecken. This counts Original Medicare only and measures volume, not quality.
- What is John Francis M. Hennecken's NPI number?
- 1104856780. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for John Francis M. Hennecken, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 219 |
|---|---|
| Services billed to Medicare | 886 |
| Different services or procedures | 13 |
| Participating Medicare provider | Yes |
| Average age of these patients | 76 |
Most frequent services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)294 services
- Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient's (G2211)219 services
- Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report (93000)169 services
- Ultrasound of heart with color-depicted blood flow, rate, direction and valve function (93306)69 services
- Insertion of needle into vein for collection of blood sample (36415)51 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High blood pressure75%
- High cholesterol75%
- Arthritis46%
- Diabetes39%
- Ischemic heart disease38%
- Chronic kidney disease26%
Practice locations
Addresses where John Francis M. Hennecken is enrolled with Medicare (CMS data updated October 2, 2026).
- 300 Cadman Plaza WBrooklyn, NY 11201 (929) 210‑6000
Group practices
Medicare enrollment lists John Francis M. Hennecken as a member of this group (CMS data updated October 2, 2026).
- Icahn School of Medicine at Mount Sinai2,843 clinicians in the group
Specialties
Find other Cardiovascular Disease (Cardiology) doctors in New York →
Other cardiologists in Brooklyn
Clinicians with the same Medicare primary specialty in Brooklyn, NY — not a recommendation.
Other clinicians in Icahn School of Medicine at Mount Sinai
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | State University Of New York Downstate Medical Center |
| Graduation year | 1981 (45 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1104856780 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians