An infill station is a train station built on an existing passenger rail, rapid transit, or light rail line to address demand in a location between existing stations. Such stations take advantage of existing train service and encourage new riders by providing a more convenient location. Many older transit systems have widely spaced stations and can benefit from infill stations. In some cases, new infill stations are built at sites where a station had once existed many years ago, for example the Cermak–McCormick Place station on the Chicago 'L''s Green Line.

Cermak–McCormick Place is a "L" station on the CTA's Green Line. The station, designed by Chicago-based Ross Barney Architects and engineered by Primary Consultant T.Y. Lin International, is located at Cermak Road and State Street in the Near South Side neighborhood of Chicago. The station includes three entrances – one on each side of Cermak Road and one at 23rd Street. The main station entrance is built on the north side of Cermak road.