Gregory J. Zweig, MD

Medicare activity in 2024

Official CMS public-use data for Gregory J. Zweig, 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. X-ray of chest, 1 view (71045)338 services
2. X-ray of chest, 2 views (71046)334 services
3. Mri scan of brain before and after contrast (70553)295 services
4. Ct scan head or brain without contrast (70450)272 services
5. Mri scan of lower spinal canal without contrast (72148)204 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%
• Arthritis61%
• Anxiety35%
• Ischemic heart disease34%
• Diabetes31%

Hospitals where Gregory J. Zweig works

Medicare's Facility Affiliation Data lists Gregory J. Zweig 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.

• Northwestern Medicine Central Dupage HospitalWinfield, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140242
• Northwestern Medicine Delnor Community HospitalGeneva, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140211
• Northwestern Memorial HospitalChicago, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140281

Practice locations

Addresses where Gregory J. Zweig is enrolled with Medicare (CMS data updated October 2, 2026).

• 825 W State St, Suite 103eGeneva, IL 60134 (630) 208‑4412

Group practices

Medicare enrollment lists Gregory J. Zweig as a member of this group (CMS data updated October 2, 2026).

• Radiology Subspecialists of Northern Illinois LLC32 clinicians in the group

Specialties

• Diagnostic Radiologyprimary

Find other Diagnostic Radiology doctors in Illinois →

Other radiologists in Geneva

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

• Kalyana C. Poruri, MD
• Michael H. Tseng, MD
• John C. Treanor, MD
• Fatma Y. Ahmed, MD
• Sharmi Jayachandran, MD
• David S. Chiang, MD
• Joseph M. Persak, MD
• Kiran V. Talanki, MD

All radiologists in Geneva →

Other clinicians in Radiology Subspecialists of Northern Illinois LLC

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

• Kalyana C. Poruri, MD
• Michael H. Tseng, MD
• Mark J. Kelly, MD
• Joyce Briscoe, MD
• Fatma Y. Ahmed, MD
• Matthew Markese, 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