The U-17 and U-18 teams play a mix agianst the NAHL, with the U-17's playing 3/4 of the games against any one opponent. The U-17 team plays all NAHL playoff games.
The U-18 team plays it's remaining games against NCAA opponents, which count as exhibition games for the NCAA team.
Both teams also compete against International U-17 and U-18 teams in various tourneys throughout the year.
Also, the lineups are not strictly age based, with Jack Johnson and Phil Kessel playing much of last year with the U-18 team. The only time that age restrictions are enforced are during the international tournaments.
Some different rules for the US teams that play in the NAHL is that they can dress up to 22 players instead of 20 (the team they play can also dress 22).
If the USA team makes the playoffs they can not advance to the National Championships. In this case which happened this past year, they defeated the Soo Indians and played Springfield for the North Division title. If Springfield would have lost, Springfield still would advance to the National Championships.
In the past 5 years the USA teams were not allowed to have a special teams group. they have to keep the same rotation weather they are a man down or a man up.
They actually play a full schedule in the NAHL and still compete in all the other events and tournaments. Most of thier games are not on the normal days that the NAHL plays. (Fri-Sun) they play a lot of weekday games to allow them to compete in other tournaments.