The NCAA allows you five years to compete in four athletic seasons, with the fifth year serving as a redshirt year. A red-shirt year allows players to sit out a year of competition (for reasons such as injury or competition for playing time) while still being able to compete athletically in all four years. As long as a player remains academically eligible throughout those five years, he can continue to play after his fourth season if he chooses to do so. A few examples of players who have competed in four years of college sport: Kevin Durant, DeMarcus Cousins, and Derrick Rose. The nature of their programs may explain why they were allowed to remain on campus for an additional year of competition. In conclusion, yes, you can play in four years of college sports.