It's a reported three-year deal worth $24 million, including $11 million guaranteed, sources tell NFL Network's Mike Garafolo.
Breeland spent the first four seasons of his career with the Redskins, starting 57 games while accumulating eight interceptions and seven forced fumbles.
Carolina was in the market for a corner after trading Daryl Worley to Philadelphia last week. The 26-year-old former fourth-round pick provides the team with a versatile option to play on the boundary or in the slot.
Meanwhile, Washington's defensive backfield will take on a much different look in 2018 without Breeland and Kendall Fuller.