The M9 is an electric multiple unit railroad car to be designed for and ordered by the Metropolitan Transportation Authority (New York) for the Long Island Rail Road as part of the 2008-2013 Capital Plan [1]. The purchase of the initial 84 M9 cars is intended to expand the Long Island Rail Road's fleet size in anticipation of the completion of the East Side Access Capital project. The additional rolling stock will address the need for additional service to Grand Central Terminal and anticipated expanded service. The projected cost of developing, designing, and constructing the first order of M9 cars is 205 million USD. The MTA plans a larger additional fleet purchase at some point to replace the aging M3 railcars, beyond the scope of the 2008-2013 Capital Plan.

Specifications for the LIRR's new cars is expected in May 2009, [2] while specifications for MNRR's cars are due in November of the same year.[3]

As this railway car model has only been noted as a projected purchase, it is subject to major changes in design.