After all of the recent headlines about the acceptance of transgender athletes (Kye Allums, Keelin Godsey, LPGA's inclusion of transgender athletes, etc.), I decided to do some research on the actual policies that govern participation.
There are three main levels of policies:
1. Olympic (IOC) and professional sports, which are the most restrictive and controversial of the three, requiring hormone treatment as well as genital reassignment surgery.
2. College sports, which rely on hormone treatment.
3. High school sports, which is the most open of the three, requiring neither hormone treatment nor genital reassignment surgery.
There isn't one policy that covers high school or college sports, rather a set of recommended policies that must be taken up by individual schools.
Policies governing Olympic and professional sports are also implemented within each individual organization.
Anyway, this takes an in depth look at high school and college sports: