The NFL had been looking into whether Buffalo violated policy on injury reporting after Hughes posted to social media that he had played the 2019 season with torn ligaments in his wrist.
Hughes' wrist problem did not appear on any injury report throughout the season. He did miss practices with a groin injury and for veteran rest days.
"The NFL confirmed that the matter was reviewed and there was no violation of the Injury Report policy," the league told the Buffalo chapter of the Pro Football Writers of America.
Hughes underwent surgery on his wrist last week. He has yet to miss a game in seven seasons with the Bills.