The FBI is investigating a case of identity theft which could involve dozens of patients at the University of Chicago Hospitals.
At least one former employee of the hospitals is accused of using confidential patient information.
U of C officials say as many as 85 patients may be affected. They are in the process of contacting each one of them.
Hospital officials are also offering to run credit reports for other patients to see if they've been victimized.
The FBI is investigating the allegations and University of Chicago Hospitals are cooperating.