Book return slots are accessible from outside each of the Library’s facilities.
It's also OK to return books to any I-Share library: https://www.carli.illinois.edu/membership/mem-libs/ishare-map Books don’t have to be returned to same location at which you picked them up. So, even if you picked up the book at a UIC library, you can return it to another i-Share library.
You can also return items by mail through the U.S. Postal Service. See the Library website for locations and mailing addresses https://library.uic.edu/libraries/.