New Bat Regulations Coming 2018Updated Friday March 4, 2016 by Chad McGinty.
Effective January 1, 2018, all 2 5/8" bats and 2 1/4" bats must meet new performance standards established by USA Baseball, the national governing body of amateur baseball in the United States.
New bats will not be manufactured until September, 2017. Any bat purchased prior to September, 2017, may not be legal in 2018.
There willl be NO phase-in period.