Traveling (competitive) Soccer, unlike some other sports, doesn't group children together by grade. Instead, they use a player's birth year to form teams entirely based on age groups. This leads to the most popular question new families ask which is "What does U mean and how do I know which age group my child should be?"
"U" stands for "Under". For example, a U9 player is a player who is Under 9 years old at the beginning of the Fall season. The player may turn 9 at any point after the beginning of the season and still be a U9 player until the beginning of the next Fall season.
The Minnesota Youth Soccer Association birthyear guide will show which age group your child would be in. If you have questions, you can contact firstname.lastname@example.org.