Karen Zimmerman, MD

Medicare activity in 2024

Official CMS public-use data for Karen Zimmerman, 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. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)566 services
2. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)350 services
3. Hospital discharge day management, more than 30 minutes (99239)117 services
4. Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes (99222)108 services
5. Hospital discharge day management, 30 minutes or less (99238)106 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%
• Arthritis69%
• Ischemic heart disease50%
• Chronic kidney disease42%
• Heart failure40%

Hospitals where Karen Zimmerman works

Medicare's Facility Affiliation Data lists Karen Zimmerman 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.

• Northwest Community Hospital 1Arlington Heights, IL · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 140252

Practice locations

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

• 2650 Ridge AveEvanston, IL 60201
• 800 W Central RdArlington Heights, IL 60005 (847) 618‑1000

Group practices

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

• Endeavor Health Medical Group3,350 clinicians in the group

Specialties

• Internal Medicineprimary

Find other Internal Medicine doctors in Illinois →

Other internal medicine doctors in Evanston

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

• Aashish K. Didwania, MD
• Prasanna S. Nair, MD
• Alex Forsyth, MD
• Valli P. Stewart, MD
• Salma A. Ferouz, MD
• John J. McAnelly, MD
• Janusz M. Dudek, MD
• Zainab Quadri, MD

All internal medicine doctors in Evanston →

Other clinicians in Endeavor Health Medical Group

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

• Patricia N. Jackson
• Zaid A. Hussain, MD
• Mark K. Kosinski, DO
• Matthew S. Pablo
• Melody S. Calla Reed, PA
• Tara C. Nikodem

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