The contract includes approximately $16 million in guaranteed money, according to reports. The sides can't make the deal official until free agency opens on Tuesday at 4 p.m. ET.
McPhee, 26, was underrated last season for the Baltimore Ravens, who had the NFL's No. 8 defense. He ranked third on the Ravens with a career-high 7.5 sacks despite playing 47.2 percent of the team's defensive snaps.
His versatility makes him a special pass-rusher. Playing with a violent style, McPhee can get to the quarterback whether he's lining up inside or on the edge.
A fifth-round pick in 2011, McPhee exploded as rookie with six sacks. But injuries limited his effectiveness in 2012 and 2013, when he combined for 3.5 sacks.
McPhee was healthy last season and continually made an impact in the pass rush. According to Pro Football Focus, his 21 quarterback hits ranked second in the NFL behind J.J. Watt.
What McPhee has to prove is whether he is a full-time player. He has made only six starts in his four-year career, and he's never had more than 27 tackles in a season.
It appears the Bears plan to use free agency to address needs up front. The club is expected to make a push for Denver Broncos free-agent defensive tackle Terrance Knighton, with ESPN's Josina Anderson reporting that the Bears have "serious interest" in bringing in Knighton to anchor the interior of Vic Fangio's 3-4 front.
Knighton played the past two seasons for new Bears coach John Fox in Denver, where he started all 32 regular-season games. Knighton finished 2014 with 30 tackles and two sacks, but he's regarded as one of the better run-stopping defensive tackles in the league.
Fox said last month at the NFL combine that he considers veteran Jeremiah Ratliff as an option to help fill the void at nose tackle. But Ratliff, 33, may be nearing the end of his career. Former second-round pick Ego Ferguson is another candidate to line up over the center, but Knighton is a proven commodity who may command in excess of $7 million per year.
ESPN.com Ravens reporter Jamison Hensley and ESPN.com Bears reporter Michael C. Wright contributed to this report.