Correia posted a 4.21 ERA with 89 strikeouts and 46 walks in 171 innings with the Pirates last season. The 32-year-old, who had a 51.2 percent ground-ball rate, which ranked tied for seventh in the National League, made 28 starts and four relief appearances in 2012.
"We've had a lot of eyes on him," Twins general manager Terry Ryan said. "He gives you a lot of innings and a lot of starts. Last year he had a solid year. They moved him to the bullpen when they acquired Wandy Rodriguez, so his innings total is a bit deceiving. But he gives you quality starts."
Correia has a 4.54 ERA with 712 strikeouts and 381 walks in 1,066 innings with the Giants, Padres and Pirates. His best season came in '09 with the Padres when he had a 3.91 ERA in 198 innings. He was also an All-Star with Pittsburgh in '11.
But this will be Correia's first time pitching for a team in the American League after spending his first 10 seasons in the National League.
"There's always some concern when a guy goes from the National League to the American League, but this guy is a veteran," Ryan said. "He'll figure it out. He throws the ball over the plate and this ballpark is conducive to him."
Ryan pointed to Correia's consistency over the past four seasons, as he's averaged 12 wins per season with a 4.51 ERA and 28 starts per year.
"He's averaged double-digit wins for the last four years," Ryan said. "If you look at his numbers, he gets you to a situation late in the game and he's consistent. He had 57 percent quality starts [16-of-28] last year and when you start getting above 50, it catches your eye."
Correia fills a major need for the Twins, as the club is looking to add to a rotation that includes only Scott Diamond and Vance Worley, who was acquired by the Twins on Dec. 6 in the trade that sent Ben Revere to Philadelphia.
Ryan said he's still on the lookout for more starting pitching, and confirmed Correia will enter the season as a likely No. 4 starter.
"He's a starter," Ryan said. "We didn't sign him to be anything but a starter."