Little League International Baseball Age Requirement
Little League International implemented a new age range for the 2017 season. The primary reason for this change is to make the Little League Baseball Division, known as the Pelham Baseball Majors Division, a 12 and under program. No child playing in this division will turn 13 years of age during their final season of eligibility. For this reason, the age cutoff for a season will change from 12/31 to 8/31 of the calendar year.
For players born on or before April 30, 2005: The new age determination date of August 31 will be effective starting with the 2018 Little League Baseball Season. For the 2016 and 2017 seasons, these players will use the April 30 age determination date.
For players born between May 1, 2005 and August 31, 2005: The new age determination date of August 31 will be effective starting with the 2019 Little League Baseball Season. For the 2016, 2017, 2018 season, these players will use the April 30 age determination date.
For players born on or after September 1, 2005: The August 31 age determination date will be effective immediately, starting with the 2016 season. This was the implementation used for the 2015 season, with players turning 4 to 9 years old during the 2015 calendar year to use the December 31 age determination date. That implementation remains in place, except instead of using December 31, you will use August 31.
Please reference this Little League International article.