The Chanticleers will begin competing in the Sun Belt in all sports but one starting in the 2016-17 season. The football team will join in 2017.
After one transition year, the football program will be eligible to compete in postseason play in the 2018 season.
"This is a great day for the Sun Belt Conference as we are very proud to have Coastal Carolina University join our membership," said Sun Belt Conference Commissioner Karl Benson when welcoming the new addition.
To meet Sun Belt standards, Coastal Carolina is expected to upgrade their football stadium to accommodate 20,000 fans. The current stadium seats 9,214 people.
The addition of Coastal Carolina will allow other sports in the conference to compete in divisional and conference title games.