Open enrollment ends at 10:59 p.m. CST on December 15 for Illinois residents. Use the federal exchange, healthcare.gov, to sign up online. Enrollment help is also available in person until 4 p.m. at the Thompson Center at 100 W. Randolph Street in Chicago. Help is also available in the Newberry Room of the Evanston Public Library at 1703 Orrington Avenue.