The lawsuit was brought on behalf of more than 5,000 retired players, though the settlement could cover more than 21,000 former players, according to the court.
Roughly 200 retirees objected to the agreement, saying it did not account for players yet to be diagnosed with CTE. They also argued the deal unfairly favored currently injured retirees and left thousands of former players who have not yet been diagnosed with neurological diseases without a remedy.
CTE has been discovered during autopsies for several former players, including Hall of Fame linebacker Junior Seau and Pro Bowl safety Dave Duerson, who both committed suicide. In March, the NFL for the first time acknowledged a link between football and CTE.
But the appeals court noted that the research surrounding CTE is still nascent, with no current way to test for the disease while an individual is still alive. It also said many of the symptoms associated with CTE, such as memory loss, are eligible for compensation under the settlement.
Earlier this year Will Smith portrayed Dr. Bennet Omalu in Concussion, a film highlighting the impact of head injuries in the NFL.