Many Chicago museums offer free admission days for Illinois Residents with a valid ID or proof of residency.
Here are the upcoming free admission days, with proof of residency:
Museum of Science and Industry: June 3-5; August 26-28.
Adler Planetarium: June 3-5, 10-13
Shedd Aquarium: June 17-18, 24-25;August 26-27 (There is a $3 transaction fee applied to free day tickets reserved online, according to the website.)
Field Museum: June 26-28
Art Institute of Chicago: General admission is free for Illinois residents from 5-8 p.m. every Thursday.
Museum of Contemporary Art: Tuesday admission is free for Illinois residents year round.