The 2013 American Le Mans Series was the fifteenth and final season of the International Motor Sports Association GT Championship being labeled as the American Le Mans Series, before merging up with the Grand-Am Rolex Sports Car Series in 2014.
As the IMSA and Grand-Am merger was announced on September 5, 2012, between NASCAR Holdings (Grand-Am's owner) and Panoz Motorsports, the 2013 season was the transition season as both series were now held under the NASCAR Holdings banner. As such, this is the 43rd season of the series dating back to the 1971 IMSA GT Championship.[1]
It began on March 16 with the 61st running of the 12 Hours of Sebring and ended with the 16th running of the Petit Le Mans on October 19. At the seventh round in Baltimore, Muscle Milk Pickett Racing successfully defended their 2012 Prototype One championship.