Quick answers
- Which hospitals does Dara B. Grennan work at?
- Medicare's official clinician data lists Dara B. Grennan at 1 hospital: John H Stroger Jr Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Dara B. Grennan see patients?
- Medicare's clinician data lists 2 practice locations, including Chicago, IL. Call before your visit to confirm the address.
- What is Dara B. Grennan's specialty?
- Medicare lists Hospitalist as the primary specialty, and also Infectious Disease and Internal Medicine.
- Does Dara B. Grennan accept Medicare assignment?
- Yes. Medicare's clinician data says Dara B. Grennan 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 Dara B. Grennan?
- (312) 633-7292, as listed in official Medicare / NPI Registry data.
- What is Dara B. Grennan's NPI number?
- 1518282938. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Dara B. Grennan works
Medicare's Facility Affiliation Data lists Dara B. Grennan at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- John H Stroger Jr HospitalChicago, IL · Acute Care Hospital · CCN 140124
Practice locations
Addresses where Dara B. Grennan is enrolled with Medicare (CMS data updated 2026-10-02).
- 1901 W Harrison StChicago, IL 60612 (312) 633‑7292
- 500 E 51st StChicago, IL 60615 (312) 572‑2000
Group practices
Medicare enrollment lists Dara B. Grennan as a member of this group (CMS data updated 2026-10-02).
- Cook County788 clinicians in the group
Specialties
- Hospitalistprimary
- Infectious Diseasealso
- Internal Medicinealso
Other hospitalists in Chicago
Clinicians with the same Medicare primary specialty in Chicago, IL — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2007 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1518282938 |
| 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