The deal is subject to a physical exam.
A four-time Gold Glove Award winner, Simmons has established himself among the most brilliant defensive shortstops in baseball history. Since his first full season in 2013, Simmons easily leads the majors with 172 defensive runs saved (Colorado Rockies third baseman Nolan Arenado is second with 120). Since entering the league in 2012, Simmons also leads MLB in defensive WAR at 26.6. The next-closest player is Kevin Kiermaier at 16.0.
Simmons, 31, will be the Twins' starting shortstop, with Jorge Polanco moving to second base and Luis Arraez still expected to get plenty of at-bats in a super-utility role. Provided that third baseman Josh Donaldson, last year's prize free agent landed by the Twins, can overcome the calf injury that limited him in 2020, the defense on the left side of the infield in Minnesota ought to be a pitcher's dream.
With Miguel Sano at first base, the Twins are on track to send out a $46 million infield for the 2021 opener.
The Los Angeles Angels acquired Simmons in November 2015 -- as the first major move by former general manager Billy Eppler -- by sending fellow shortstop Erick Aybar and top prospect Sean Newcomb to the Atlanta Braves.
Simmons batted .281/.328/.394 in his five seasons with the Angels, compiling 36 homers, 112 doubles and 15.4 FanGraphs wins above replacement, ninth-most among shortstops from 2016 to 2020.
Entering 2020, Simmons was one of four players with a contact rate of 85% or better in eight straight seasons. The others were Michael Brantley, Daniel Murphy and Dustin Pedroia. Simmons' contact rate went under 85% in 2020, but he played in just 30 games, missing time due to an ankle he injured for a third straight summer. With Los Angeles' postseason chances dwindling, he opted out of the final week of the season.
A native of Curacao, Simmons, was selected by Atlanta in the second round of the 2010 amateur draft and made his big league debut with the Braves in 2012. He is a .269 career hitter with 67 homers and 406 RBIs in 1060 games with the Braves and Angels.
ESPN's Alden Gonzalez, ESPN Stats & Information and The Associated Press contributed to this report.