Obama was treated in the doctor's office on the ground floor of the White House. He had gone to Fort McNair with family and friends for a morning game of hoops.
The injury happened in the last of five games they played. Obama was playing defense when Decerega turned to take a shot and elbowed the president in the mouth.
"I learned today the president is both a tough competitor and a good sport. I enjoyed playing basketball with him this morning. I'm sure he'll be back out on the court again soon," Decerega said in a statement.
According to the White House, some of the players included: the president's nephew, Avery Robinson, Reggie Love and Education Secretary Arne Duncan.
Obama is a sports fan, roots for his hometown Chicago teams and has often gone golfing in addition to playing basketball.
The Associated Press contributed to this report.