On July 10th, 2019, the entry list for the event was released, featuring 22 cars. There were eight cars entered in GTLM, and 14 in GTD. The most notable change to the grid included the return of Blancpain GT World Challenge America full-time team Wright Motorsports, with drivers Anthony Imperato and Porsche Junior Professional driver Matt Campbell. Pfaff Motorsports regular driver Scott Hargrove would sit out the Lime Rock Park event as well as the following event at Road America, replaced instead by Porsche Junior driver Dennis Olsen for the Lime Rock event. Olsen and Campbell are set to switch places for Road America. Due to this event happening 50 years and one day after the Apollo 11 moon landing, GTD team Magnus Racing decided to commemorate the anniversary of the mission by launching a one-off livery designed to look like the Saturn V rocket, and run under the number 11. As Magnus Racing usually ran under car number 44, the team received special dispensation by IMSA to count the points they would score as number 11 towards their full-season points under number 44.
