Odyssey of the Mind teams are divided into four divisions: Division I, roughly corresponding to elementary school ages, Division II for middle school, Division III for high school, and Division IV for college. The requirements are structured so that students may compete at higher levels than they typically would, with the exception of Division IV which has more specific requirements. They may not, however, participate in a lower levels; for example, a student of the right age for Division II could compete in Divisions II, III, but not Division I. Division IV is specifically for college students and therefore requires a high school diploma or GED and enrollment in at least one college class.
There is also a non-competitive primary division; this is for young children, who are given a simplified problem and fewer constraints than the higher divisions. They present and are given feedback at the first level tournament and cannot advance.
In the United States, each participating state has its own Odyssey organization. Most states are further broken down into regions. Teams compete at the regional level first and then, if they win, progress to the state level. In the USA, there is no national level. State-winning teams go directly to the World Finals, which have always been held in the USA, usually near the end of May. The World Finals for the 2006–07 school year will be held from May 23–26, 2007, at Michigan State University in East Lansing, Michigan.