The Boston Athletic Association (B.A.A.) today announced that registration for the 13th B.A.A. Half Marathon, presented by Dana-Farber Cancer Institute and the Jimmy Fund, has closed after its 7,500 entrant field size limit was reached. The B.A.A. Half Marathon will be held on Sunday, October 13, 2013 and will be the third and final race in the 2013 B.A.A. Distance Medley. Registration opened on Wednesday, July 17 at 10:00 a.m. ET and closed approximately 12 minutes later at 10:12 a.m. ET.