22 Allergy & Immunology (Internal Medicine) providers practice in Illinois, including 6 (27%) offering telehealth. The largest concentration is in Chicago. Profiles include federal Open Payments records of money received from drug and device companies in 2025. Listings are drawn from federal public records and are not endorsements.
Choose a city to see providers there.
From CMS Medicare enrollment records covering 16 of the 22 providers listed here (73%). Providers who do not bill Medicare are not included in these figures.
| Group (as registered with Medicare) | Allergists (Internal Medicine) | All clinicians in group | Main city |
| Rush University Medical Group | 4 | 1,521 | Chicago |
| Hospital | City | Ownership | CMS star rating | Allergists (Internal Medicine) affiliated |
| Northwestern Medicine Central Dupage Hospital | Winfield | Nonprofit | 5 of 5 | 4 |
| Rush University Medical Center | Chicago | Nonprofit | 5 of 5 | 4 |
| Rush Oak Park Hospital | Oak Park | Nonprofit | 4 of 5 | 2 |
Sources: CMS Doctors and Clinicians (August 2026) and Facility Affiliation files (August 2026); hospital ownership type and overall star rating from CMS Hospital General Information (July 2026). A clinician in several groups is counted once, in the largest group they bill through. Ownership type is what the hospital reports to CMS; it does not show private equity or other investor ownership. How we build this directory.
Listed by city, largest first. Payment figures come from the federal Open Payments program, which requires drug and device companies to report what they pay physicians for consulting, speaking, meals, travel and royalties. A disclosed payment is a financial relationship, not evidence of wrongdoing, and many totals reflect a single meal. Figures cover calendar year 2025.
There are 22 Allergy & Immunology (Internal Medicine) providers with active NPI records practicing in Illinois, according to federal NPPES data refreshed monthly.
Yes. 6 of the 22 Allergy & Immunology (Internal Medicine) providers in Illinois (about 27%) report offering telehealth services in CMS data.
Chicago (12), Bloomingdale (1), Winnetka (1) have the highest concentration of Allergy & Immunology (Internal Medicine) providers in Illinois.
Provider counts and profiles come from the federal NPPES registry and CMS Doctors and Clinicians files. Payment figures come from the CMS Open Payments program for calendar year 2025. The directory refreshes monthly.
Among 16 Allergists (Internal Medicine) in Illinois enrolled in Medicare, 31% bill through a solo or small practice with fewer than 10 clinicians, 6% through a mid-size group of 10 to 99, and 63% through a large group or health system with 100 or more clinicians, according to CMS enrollment records.
According to CMS facility affiliation records, the Illinois hospitals where the most Allergists (Internal Medicine) hold privileges are Northwestern Medicine Central Dupage Hospital in Winfield; Rush University Medical Center in Chicago; Rush Oak Park Hospital in Oak Park.
Allergy & Immunology (Internal Medicine) in all 50 states Search all 22 in the directory Ask Zach for help choosing