Feliks S. Mavashev, MD

Medicare activity in 2024

Official CMS public-use data for Feliks S. Mavashev, 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)1,308 services
2. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)613 services
3. Injection of drug or substance under skin or into muscle (96372)508 services
4. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)462 services
5. Blood glucose (sugar) test performed by hand-held instrument (82962)448 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%
• Arthritis75%
• Anxiety54%
• Diabetes50%
• Ischemic heart disease37%

Hospitals where Feliks S. Mavashev works

Medicare's Facility Affiliation Data lists Feliks S. Mavashev 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.

• Northshore University Healthsystem - Evanston HospitalEvanston, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140010
• Presence Saint Joseph Hospital - ChicagoChicago, IL · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 140224
• Saint Francis Hospital-EvanstonEvanston, IL · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 140080
• Swedish HospitalChicago, IL · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 140114
• Thorek Memorial HospitalChicago, IL · Acute Care Hospital · Emergency services: listed by Medicare · CCN 140115

Practice locations

Addresses where Feliks S. Mavashev is enrolled with Medicare (CMS data updated October 2, 2026).

• 1007 W Lawrence AveChicago, IL 60640 (773) 271‑1500

Specialties

• Internal Medicineprimary

Find other Internal Medicine doctors in Illinois →

Other internal medicine doctors in Chicago

Clinicians with the same Medicare primary specialty in Chicago, IL — not a recommendation.

• Nicole D. King, MD
• Andrew S. Crone, MD
• Predrag Z. Simovic, MD
• Nikita Pillai, MD
• Jennifer R. Goldfarb, MD
• Anna Volerman Beaser, MD
• Hasan Abad, DO
• Rebeca X. Ortiz Worthington, MD

All internal medicine doctors in Chicago →

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