The deal was announced on Wednesday.
The 26-year-old McPhee spent four seasons in Baltimore and played for a Super Bowl champion. Chicago has a new coach in John Fox and general manager in Ryan Pace. The Bears, coming off a five-win season, are switching from a 4-3 to a 3-4 defense. The Bears allowed the most points in franchise history in 2013 and second-most last season.
McPhee set career highs for Baltimore last season with 27 tackles, 7 1/2 sacks, four pass breakups and 11 tackles for loss. He had 92 tackles, 17 sacks and 24 tackles for loss with the Ravens.
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