Here is the verbiage for the new bat rules.
*Starting January 1, 2018 USA Baseball is instituting a new bat standard which will be approved for play in AABC Baseball, Babe Ruth & Cal Ripken, Dixie Youth Baseball & Dixie Boys Baseball, Little League Baseball* (all divisions except Senior League) and PONY Baseball.
*Barrels up to 2-5/8″ are now approved for ages 14 and under.
*Players will need a new bat stamped with the new USA Baseball Mark.
*New USA Baseball approved bats will be available for purchase on September 1, 2017.