http://www.usatoday.com/story/sports/olympics/rio-2016/2016/07/19/out-transgender-olympics-rio-caitlyn-jenner-chris-mosier/87188798/Erik Brady wrote:
those who transition from female to male are eligible to compete without restriction and those who transition from male to female are eligible to compete without gender reassignment surgery and with one year of hormone therapy.... The new guidelines, which also require certain specified low levels of testosterone, reflect changing attitudes globally.