Jillian L. Marousek, MD

Medicare activity in 2024

Official CMS public-use data for Jillian L. Marousek, 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. Anesthesia for lens surgery (00142)73 services
2. Anesthesia for other procedure on esophagus, stomach, or upper small bowel using an endoscope (00731)14 services
3. Anesthesia for other procedure on large bowel using an endoscope (00811)12 services
4. Injection of anesthetic agent and/or steroid into arm nerve bundle (brachial plexus) (64415)11 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%
• Arthritis56%
• Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)25%
• Ischemic heart disease23%
• Diabetes22%

Hospitals where Jillian L. Marousek works

Medicare's Facility Affiliation Data lists Jillian L. Marousek 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.

• Greenwich Hospital Association -Greenwich, CT · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 070018

Practice locations

Addresses where Jillian L. Marousek is enrolled with Medicare (CMS data updated October 2, 2026).

• 5 Perryridge RdGreenwich, CT 06830 (203) 661‑5330

Group practices

Medicare enrollment lists Jillian L. Marousek as a member of this group (CMS data updated October 2, 2026).

• Greenwich Anesthesiology Associates PC42 clinicians in the group

Specialties

• Anesthesiologyprimary

Find other Anesthesiology doctors in Connecticut →

Other anesthesiologists in Greenwich

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

• Edwin Oh, MD
• Jared W. Rosenberg, MD
• Terry L. Cochran, MD
• Elvis E. Umanzor-Velasquez, MD
• Mark Chrostowski, MD
• David M. Shapiro, MD
• Marc A. Gurny, MD
• Tiffany T. Denepitiya-Balicki, MD

All anesthesiologists in Greenwich →

Other clinicians in Greenwich Anesthesiology Associates PC

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

• Edwin Oh, MD
• Ricky G. Ewell Ii, CNA
• Jared W. Rosenberg, MD
• Tiffany T. Denepitiya-Balicki, MD
• Michael F. Levin, MD
• Lucas Bejar, MD

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