Miller posted a photo of himself in a Commanders uniform as the two sides are currently "finalizing" the details of the deal.
The three-time All-Pro defensive end was originally selected with the No. 2 pick in the 2011 NFL Draft by the Denver Broncos, where he would go on to spend 10 years with, reaching the Pro Bowl in eight of them.
After earning Super Bowl MVP with the Broncos to cap off the 2016 season, Miller would eventually be traded to the Los Angeles Rams halfway through the 2021 season - where he would go on to win his second ring.
Miller spent the past three seasons (2022-2024) as a member of the Buffalo Bills. He posted six sacks and 17 tackles in 13 games this past season and will now be joining the Commanders for his 14th year in the league.
This year will mark Miller's 14th year in the league as he currently ranks 25th on the all-time sacks list with 129.5 and is a member of the Hall of Fame All-2010s team