The 31-year-old defender made the announcement Monday on social media. Moats did not play in 2018 after getting cut in October by the Arizona Cardinals. The sixth round pick in the 2010 NFL Draft played his first four seasons with the Bills, before joining the Steelers in 2014.
Moats had 2020 tackles, 16.5 sacks, 15 tackles for a loss, six passes defensed, four forced fumbles and four fumble recoveries in 121 games during his NFL career.
The 6-foot, 246-pound linebacker included a video of his career highlights in the social media post.
"It's been an awesome run and I've been blessed to have lived out my dream of playing in the NFL for nine incredible seasons," Moats wrote. "The lifelong bonds I've made throughout this journey I will forever hold near and dear to my heart. I have to give a big thanks to the Buffalo Bills and the Pittsburgh Steelers for giving me this opportunity to not only live out my dream on the field but to have a platform to positively impact people off it!"
"Last but certainly not least, I have to give a big shoutout to two of the best fan bases in all of professional sports with Bills Mafia and Steelers Nation! The support I've received throughout my playing career and up until now has been nothing short of amazing! All love!"
Moats' posts included well-wishes from several former teammates, including T.J. Watt, Bud Dupree and Rosie Nix.