USAC is responsible for staffing events at the Indianapolis Motor Speedway. In 2015 that includes both the IMSA and IncyCar events that utilize the inner track.
United States Auto Club (USAC) was created to compete with the Sports Car Club of America (SCCA) however in it’s present form it acts as an organizing body for marshals wishing to work Indianapolis Motor Speedway events. USAC organized marshals for such events as Grand Am and MotoGP when they ran at Indy. They were also instrumental in organizing the Detroit Belle Isle Grand Prix and the United State F1 Grand Prix at the Circuit of the Americas.
What must you do to join this club?
You join the club only for the sake of participating a specific event. Therefore you register by filling out the forms on their web site: http://www.motogpworker.com/ send in your payment for the registration and wait for the e-mail confirmation if you are selected to participate.
What must you do to qualify to work a Pro event?
The selection criteria for any particular event probably depends on how many people are required to staff the event and what background the candidates posses as it relates to the event. For example for MotoGP it was obvious that many motorcycle fans and riders were selected without much prior experience in marshaling. However, the people selected were very familiar with the riders, the motorcycles raced and the series as a whole. A training DVD was sent out to all accepted candidates to allow them to brush up their understanding of what flags are used and what the response procedures were. The video was extremely informative.
What does it cost to join this club?
The fee changes depending on how many events you decide to participate in. In the past a single race was about $30 fee, another was $25 but if you signed up for both it was only $35 or something along those lines. These figures may not be accurate but give you a ballpark figure of what to expect.