Each referee over the age of eighteen must go through the Risk Management procedure with USSF during the registration or recertification Process.
It is important to note that while an individual referee may be asked to explain an issue in their background, it does not mean the/she will be denied officiating privileges. Referees may appeal a negative decision.
The United States Soccer Federation has mandated that all certified referees are required to take the Concussion Course. It is a simple online module conducted as part of your yearly registration.