Quick answers
- Does John P. Karagiannis accept Medicare assignment?
- Yes. Medicare's clinician data says John P. Karagiannis 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 P. Karagiannis see?
- In 2024, CMS data shows 627 Original Medicare patients and 5,375 services for John P. Karagiannis. This counts Original Medicare only and measures volume, not quality.
- What is John P. Karagiannis's NPI number?
- 1386647170. 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 P. Karagiannis, 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 | 627 |
|---|---|
| Services billed to Medicare | 5,375 |
| Different services or procedures | 95 |
| Participating Medicare provider | Yes |
| Average age of these patients | 75 |
Most frequent services
- Injection, gadobutrol, 0.1 ml (A9585)2,000 services
- Low osmolar contrast material, 300-399 mg/ml iodine concentration, per ml (Q9967)1,475 services
- Routine electrocardiogram (ecg) using at least 12 leads with tracing (93005)316 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)243 services
- Insertion of needle into vein for collection of blood sample (36415)178 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%
- Arthritis42%
- Ischemic heart disease37%
- Diabetes29%
- Chronic kidney disease24%
Hospitals where John P. Karagiannis works
Medicare's Facility Affiliation Data lists John P. Karagiannis 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.
- Community Hospital of Bremen IncBremen, IN · Critical Access Hospital · Emergency services: listed by Medicare · CCN 151300
- Elkhart General HospitalElkhart, IN · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 150018
Practice locations
Addresses where John P. Karagiannis is enrolled with Medicare (CMS data updated October 2, 2026).
- 303 N Nappanee StElkhart, IN 46514
- 621 Memorial Dr, Suite 511South Bend, IN 46601 (574) 544‑5580
Group practices
Medicare enrollment lists John P. Karagiannis as a member of these groups (CMS data updated October 2, 2026).
- Beacon Medical Group Inc589 clinicians in the group
- Privia Medical Group Indiana LLC28 clinicians in the group
Specialties
- Gastroenterologyprimary
Other gastroenterologists in Indiana
Clinicians with the same Medicare primary specialty in Indiana — not a recommendation.
Other clinicians in Beacon Medical Group Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Loyola University Of Chicago, Stritch School Of Medicine |
| Graduation year | 1987 (39 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1386647170 |
| 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