To be eligible, players must be 18 years or younger as of August 1st of the season year. However, 19-year-old players to be on the 21 man roster provided they meed a set of criteria specified in the official rulebook.
All players must be 18 years of age or younger. There are some exceptions regarding players who are 19 years of age depending on whether or not their birthday falls on or after August 1st.
The Joe DiMaggio Baseball League allows that players be 18 years of age or under. Players that turn 19 before the baseball league starts are eligible to play that year.
