The CTA ordered 100 new 3200-series cars from Morrison-Knudsen in the early 1990s, coinciding with the opening of the new Orange Line to Midway Airport. These cars are similar to the 2600-series cars, except that the 3200s have corrugated exterior panels to discourage graffiti. The 3200s can currently be found in service on the Brown, Yellow and Orange lines.
A number of 3200s were delivered with pantographs and other electrical equipment for use on the Yellow Line, which originally was powered by overhead wires. However, the Yellow Line was converted to conventional third-rail operation and the pantographs were removed.