Quick answers
- Which hospitals does Jeffrey L. Grassle work at?
- Medicare's official clinician data lists Jeffrey L. Grassle at 1 hospital: Northwestern Lake Forest Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Jeffrey L. Grassle see patients?
- Medicare's clinician data lists 2 practice locations, including Grayslake, IL and Lake Forest, IL. Call before your visit to confirm the address.
- What is Jeffrey L. Grassle's specialty?
- Medicare lists Emergency Medicine as the primary specialty, and also Internal Medicine.
- Does Jeffrey L. Grassle accept Medicare assignment?
- Yes. Medicare's clinician data says Jeffrey L. Grassle accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for Jeffrey L. Grassle?
- (312) 926-6146, as listed in official Medicare / NPI Registry data.
- What is Jeffrey L. Grassle's NPI number?
- 1205802147. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Jeffrey L. Grassle works
Medicare's Facility Affiliation Data lists Jeffrey L. Grassle at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Northwestern Lake Forest HospitalLake Forest, IL · Acute Care Hospital · CCN 140130
Practice locations
Addresses where Jeffrey L. Grassle is enrolled with Medicare (CMS data updated 2026-10-02).
- 1475 E Belvidere RdGrayslake, IL 60030
- 660 N Westmoreland Rd, 302 Lake Forest ObgynLake Forest, IL 60045 (312) 926‑6146
Group practices
Medicare enrollment lists Jeffrey L. Grassle as a member of this group (CMS data updated 2026-10-02).
- Northwestern Medical Faculty Foundation4,503 clinicians in the group
Specialties
- Emergency Medicineprimary
- Internal Medicinealso
Other emergency medicine doctors in Illinois
Clinicians with the same Medicare primary specialty in Illinois — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Kansas School Of Med (kc/wich/sal) |
| Graduation year | 1985 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1205802147 |
| Corrections | Report an error or suggest an update → |
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
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians