The M&M Subdivision is a railroad line owned by CSX Transportation in the U.S. State of Alabama. The line runs from Montgomery, Alabama to Mobile, Alabama for a total of 178.2 miles. At its north end it continues south from the S&NA South Subdivision and at its south end it continues south as the NO&M Subdivision. There is also the Prattville Branch which runs from Montgomery, Alabama to Prattville, Alabama for a total of 12.0 miles.