A formal assessment is conducted by a licensed assessor who observes a team of officials during a match. After the match, the assessor provides feedback (both verbal and written) to each referee and referee administration on each referee's strengths, and areas and suggestions for improvement. An assessment is a very useful tool to help the referee identify those areas in which they do well, and those areas where improvement can be made to strengthen the referee's performance and suggestions as to how to achieve those improvements. Formal assessments also help the referee administration determine if the referee should be promoted in grade and/or assigned/offered higher-level games.

Formal assessments are required when a referee wants to upgrade from their current grade to the next higher grade. Additionally, formal assessments are required annually for USSF Grade 6 (State) referees to maintain their grade. USSF Grades 8 and 7 referees are not required to have annual assessments to maintain their licenses.