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.
At the fall 2015 meeting of the Little League International Board of Directors, it was approved to grandfather the four months of children born between May 1 and August 31, 2005, for the 2018 season, so that no child will lose their 12-year-old season of Little League Baseball.