The M9 is a class of electric multiple unit railroad cars being built by Kawasaki Heavy Industries for use on the MTA's Long Island Rail Road (LIRR) and Metro-North Railroad. They entered service September 11, 2019. These cars will replace the M3/M3A railcars built during the early 1980s, as well as expand the LIRR fleet to provide additional service after the completion of the LIRR's East Side Access project. A separate order of cars purchased for the LIRR and Metro-North using federal funding for the East Side Access project will also be designated M9A.