Lee M. Demertzis, MD

Medicare activity in 2024

Official CMS public-use data for Lee M. Demertzis, 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. Critical care, first 30-74 minutes (99291)150 services
2. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)59 services
3. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)54 services
4. Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes (99223)19 services
5. Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes (99222)12 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%
• Heart failure60%
• Chronic kidney disease57%
• Diabetes55%
• Arthritis55%

Hospitals where Lee M. Demertzis works

Medicare's Facility Affiliation Data lists Lee M. Demertzis 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.

• Mercy Hospital SouthSaint Louis, MO · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 260077
• Parkland Health CenterFarmington, MO · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 260163

Practice locations

Addresses where Lee M. Demertzis is enrolled with Medicare (CMS data updated October 2, 2026).

• 10010 Kennerly RdSaint Louis, MO 63128 (314) 525‑4137

Group practices

Medicare enrollment lists Lee M. Demertzis as a member of this group (CMS data updated October 2, 2026).

• Mercy Clinic Adult Critical Care LLC60 clinicians in the group

Specialties

• Critical Care (Intensivists)primary
• Internal Medicinealso
• Pulmonary Diseasealso

Find other Critical Care (Intensivists) doctors in Missouri →

Other critical care doctors in Saint Louis

Clinicians with the same Medicare primary specialty in Saint Louis, MO — not a recommendation.

• Francis D. Ntimba, MD
• Anne Wyman, MD
• Justin G. Knittel, MD
• Sanjay Subramanian, MD
• Sarah E. Kavanagh, MD
• Fajun Wang, MD
• Terrance T. Kummer, MD
• Jessica L. Nelson, MD

All critical care doctors in Saint Louis →

Other clinicians in Mercy Clinic Adult Critical Care LLC

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

• Lauren Wiley, PA
• Anne Wyman, MD
• Ashwani K. Joshi, MD
• Randall C. Speck, MD
• Alayna Titus, PA
• Praveen Datar, 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