Quick answers
- Does Theofanis Tsiamtsiouris accept Medicare assignment?
- Yes. Medicare's clinician data says Theofanis Tsiamtsiouris 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 Theofanis Tsiamtsiouris see?
- In 2024, CMS data shows 1,363 Original Medicare patients and 4,923 services for Theofanis Tsiamtsiouris. This counts Original Medicare only and measures volume, not quality.
- What is Theofanis Tsiamtsiouris's NPI number?
- 1306897541. 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 Theofanis Tsiamtsiouris, 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 | 1,363 |
|---|---|
| Services billed to Medicare | 4,923 |
| Different services or procedures | 41 |
| Participating Medicare provider | Yes |
| Average age of these patients | 77 |
Most frequent services
- Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report (93000)1,818 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)872 services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)566 services
- Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more (99215)466 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)395 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%
- Ischemic heart disease65%
- Arthritis52%
- Diabetes37%
- Atrial fibrillation33%
Hospitals where Theofanis Tsiamtsiouris works
Medicare's Facility Affiliation Data lists Theofanis Tsiamtsiouris at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Good Samaritan Hospital Medical CenterWest Islip, NY · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 330286
- Mercy Medical CenterRockville Centre, NY · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 330259
- St Francis Hospital - The Heart CenterRoslyn, NY · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 330182
Practice locations
Addresses where Theofanis Tsiamtsiouris is enrolled with Medicare (CMS data updated October 2, 2026).
- 100 Port Washington BlvdRoslyn, NY 11576
- 1000 N Village AveRockville Center, NY 11570
- 1405 Old Northern BlvdRoslyn, NY 11576 (516) 484‑6777
- 16303 Horace Harding Expy, Suite 100Fresh Meadows, NY 11365 (718) 454‑4600
- 2200 Northern BlvdGreenvale, NY 11548
Group practices
Medicare enrollment lists Theofanis Tsiamtsiouris as a member of this group (CMS data updated October 2, 2026).
- CHS Physician Partners PC743 clinicians in the group
Specialties
Other interventional cardiologists in Roslyn
Clinicians with the same Medicare primary specialty in Roslyn, NY — not a recommendation.
Other clinicians in CHS Physician Partners PC
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | State University Of New York At Stony Brook, School Of Medicine |
| Graduation year | 1993 (33 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1306897541 |
| 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
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- 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