Quick answers
- Does Vassilis J. Siomos accept Medicare assignment?
- Yes. Medicare's clinician data says Vassilis J. Siomos 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 Vassilis J. Siomos see?
- In 2024, CMS data shows 365 Original Medicare patients and 1,156 services for Vassilis J. Siomos. This counts Original Medicare only and measures volume, not quality.
- What is Vassilis J. Siomos's NPI number?
- 1598907149. 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 Vassilis J. Siomos, 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 | 365 |
|---|---|
| Services billed to Medicare | 1,156 |
| Different services or procedures | 63 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)273 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)171 services
- Diagnostic exam of bladder and urethra using an endoscope (52000)60 services
- Ultrasound measurement of bladder capacity after voiding (51798)59 services
- Electronic assessment of bladder emptying (51741)56 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 cholesterol68%
- High blood pressure65%
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)41%
- Arthritis39%
- Ischemic heart disease27%
- Diabetes23%
Hospitals where Vassilis J. Siomos works
Medicare's Facility Affiliation Data lists Vassilis J. Siomos 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.
- Cabinet Peaks Medical CenterLibby, MT · Critical Access Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 271320
- Clark Fork Valley HospitalPlains, MT · Critical Access Hospital · Emergency services: listed by Medicare · CCN 271323
- Logan Health - WhitefishWhitefish, MT · Critical Access Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 271336
- Logan Health Medical CenterKalispell, MT · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 270051
Practice locations
Addresses where Vassilis J. Siomos is enrolled with Medicare (CMS data updated October 2, 2026).
- 1600 Hospital WayWhitefish, MT 59937 (406) 863‑3500
- 298 Osloski RdEureka, MT 59917 (406) 297‑7713
- 310 Sunnyview LnKalispell, MT 59901
- 320 Sunnyview LnKalispell, MT 59901 (406) 756‑3526
- 350 Heritage WayKalispell, MT 59901
Group practices
Medicare enrollment lists Vassilis J. Siomos as a member of this group (CMS data updated October 2, 2026).
- Kalispell Regional Medical Center Inc421 clinicians in the group
Specialties
- Urologyprimary
Other urologists in Montana
Clinicians with the same Medicare primary specialty in Montana — not a recommendation.
Other clinicians in Kalispell Regional Medical Center 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 | 2009 (17 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1598907149 |
| 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