This table shows the appropriate US Soccer age group for a player born in the given birthyear.

It reflects the U.S. Soccer nomenclature for naming age groups. e.g. "10U" means players will be "10 or Under" by the end of the year-long "soccer season" (which is Fall and the following Spring season). Previously, "U10" meant the player would be "Under 10" at the start of the same year-long soccer season. Yes, it means exactly the same thing...