If you are on active duty visiting the local Chicago area but live outside the area, you don't need a pass - just show your ID. You can also ride for free if you are in uniform. Retirees are not eligible unless you are rated as a disabled veteran.
567 West Lake Street, Chicago
The Chicago Transit Authority has a free military service pass for active duty personnel and qualified disabled veterans that are traveling on trains and buses in the local area. Veterans must be rated disabled 10% or greater. You must visit an authorized CTA center to get a season pass.