Nikolaos Vassiliou, MD

Medicare activity in 2024

Official CMS public-use data for Nikolaos Vassiliou, 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.

Most frequent services

1. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)91 services
2. Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit (G0439)50 services
3. Annual depression screening, 5 to 15 minutes (G0444)35 services
4. Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more (99215)28 services
5. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)26 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 cholesterol75%
• High blood pressure63%
• Arthritis42%
• Ischemic heart disease33%
• Diabetes28%
• Anxiety20%

Hospitals where Nikolaos Vassiliou works

Medicare's Facility Affiliation Data lists Nikolaos Vassiliou 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.

• Middlesex HospitalMiddletown, CT · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 070020

Practice locations

Addresses where Nikolaos Vassiliou is enrolled with Medicare (CMS data updated October 2, 2026).

• 270 Main St, Suite APortland, CT 06480 (860) 358‑5040
• 80 Shunpike Rd, Unit 301Cromwell, CT 06416 (860) 358‑5020

Group practices

Medicare enrollment lists Nikolaos Vassiliou as a member of this group (CMS data updated October 2, 2026).

• MHS Primary Care, Inc.180 clinicians in the group

Specialties

• Family Practiceprimary

Find other Family Practice doctors in Connecticut →

Other family doctors in Portland

Clinicians with the same Medicare primary specialty in Portland, CT — not a recommendation.

• Jessica Reichbind, DO
• Stephen J. Siegel, MD
• Otto Weis, MD
• Yadira E. Acevedo, MD
• Kristen Donato, DO
• Adam Seidner, MD
• Alexandra A. Carlson, MD
• Marc Roy

All family doctors in Portland →

Other clinicians in MHS Primary Care, Inc.

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

• Thomas E. Gorsky
• Matthew F. Nichols, MD
• Jessica M. Bautista
• Jennifer P. Swenson, MD
• Katherine S. Erikson, PA
• Marguerite M. Lamb

Clinician information

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

1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
6. Medicare Care Compare — official Medicare tool to look up clinicians