The whole thing just some food for thought
League and Association Play. Leagues and associations should organize competition by age, and consider physical, cognitive, and emotional maturity when grouping players. For leagues or associations in which some local programs choose to organize their teams by grade, those teams should play in the age division determined by the oldest player on their roster.

Teams organized by single birth year or single grade are suggested, but if a league needs to group two years/grades together, it should strive to limit the maximum age difference between players in a youth game to no more than twenty-four (24) months.

Players who are participating in any high school level program such as a high school freshman, JV-B, junior varsity, varsity or club team should not be eligible for U15 competition in the same season. This means that a player who is age eligible for U15 but plays on a high school level team should not concurrently play on a youth league U15 team. At other times of the year this player may be U15 eligible, for example, for summer ball or fall ball play, depending on the guidelines of the sponsoring league or organization.

The following age groupings are determined as of the August 31st preceding competition:

NOTE: Age group references used in this section are in common usage but should not be understood literally. The U15 (read: "Under 15") grouping means that, if a player is 14 years old on the cutoff date, he/she may participate in U15 competition as a 15-year old.

U15:
All players must be 14 years old or younger on the August 31st preceding competition. It is recommended that when multiple teams exist within a program, the program should consider physical size, skill, and maturity when organizing teams.

U13:
All players must be 12 years old or younger on the August 31st preceding competition. It is recommended that when multiple teams exist within a program, the program should consider physical size, skill, and maturity when organizing teams.

U11:
All players must be 10 years old or younger on the August 31st preceding competition. It is recommended that when multiple teams exist within a program, the program should consider physical size, skill, and maturity when organizing teams.

U9:
All players must be 8 years old or younger on the August 31st preceding competition. It is recommended that when multiple teams exist within a program, teams should consider physical size, skill, and maturity.

NOTE: Age group references used in this section are in common usage but should not be understood literally. The U15 (read: "Under 15") grouping means that, if a player is 14 years old on the cutoff date, he may participate in U15 competition as a 15-year old.

Special Consideration
Although it is not recommended that any athlete play below his age group, US Lacrosse recognizes the need for special consideration due to the physical and/or cognitive development of an athlete. It would be up to the league to establish a waiver process through which it can review such cases. Ultimately it is up to the league and athlete’s parents to come to an agreement.