during a 27-20 week 1 loss to the miami dolphins, lewan suffered a concussion after a blind side hit by andre branch. lewan missed the rest of the game and the next game against the houston texans. he returned from concussion protocol prior during week 3 against the jacksonville jaguars. branch was fined $10,026 for taunting following the hit. during a 13-12 week 5 loss to the buffalo bills, lewan left the game early due to a foot injury. he had a mri, but returned the next week against the baltimore ravens. on december 18, 2018, lewan was selected to his third consecutive pro bowl. the titans missed the playoffs due to a 33-17 loss to the indianapolis colts in week 17, finishing with a 9-7 record for the third consecutive year. lewan finished the 2018 season starting 15 out of 16 games. he was ranked 77th by his fellow players on the nfl top 100 players of 2019.