Per NFL Network's Ian Rapoport, Breeland is expected to join the Panthers when free agency officially begins on Wednesday.
Mike Garafolo of NFL Network reported it's a three-year deal worth $24 million with $11 million in guaranteed money.
Breeland spent the first four years of his NFL career with Washington. Despite being a fourth-round draft pick in 2014, he quickly emerged as a valuable asset on defense with 15 starts as a rookie.
Last season was one of Breeland's most productive, despite recording just one interception in 15 games. The 26-year-old finished fifth in the NFL with a career-high 19 passes defensed.
Breeland has found success, particularly when playing in the slot. Per Pro Football Focus, no cornerback allowed a lower passer rating in the slot during the 2016 season than Breeland:
Given his age and consistent level of performance throughout his career, Breeland was one of the most impactful free agents on the market. He's also been a durable presence in the lineup with only four missed games in four seasons.
The Panthers entered this offseason in search of an upgrade in the secondary. Breeland will potentially occupy the No. 1 cornerback spot in Carolina two years after Josh Norman left the Panthers to play alongside him in Washington.
Carolina struggled against the pass last season, finishing 18th in passing yards allowed (3,665) and 21st in opponent completion percentage (63.8).
Coming off an 11-5 record and playoff appearance in 2017, the Panthers are trying to strike while the iron is hot as they fight with the New Orleans Saints and Atlanta Falcons for NFC South supremacy.