Correia, 30, posted a 12-11 record with a 3.91 ERA in 2009 for San Diego before slumping to 10-10 with a 5.40 ERA last season. Correia missed nearly two weeks in May when his brother Trevor, 21, suffered an accidental death in a fall from a cliff during a hiking trip in California. But he still managed to make 28 appearances and log 145 innings for the Padres.
Correia, who broke into professional ball as a fourth-round pick with San Francisco in 2002, has a 36-43 record with a 4.57 ERA in parts of eight seasons with the Giants and Padres. He earned $3.6 million last season.
Pittsburgh general manager Neal Huntington has been trying to upgrade a struggling pitching rotation on a limited budget this winter. Pittsburgh's starters posted an aggregate 34-84 record with a 5.28 ERA last season.
Correia slots in near the front of a Pittsburgh rotation that also includes Paul Maholm and James McDonald. Ross Ohlendorf, Charlie Morton and Brad Lincoln are expected to compete for jobs in spring training.
Pittsburgh also has a one-year deal with left-hander Scott Olsen, who also must pass a physical. Olsen was 6-12 over the last two seasons for Washington, which removed him from its 40-man roster on Nov. 5.
Meanwhile, a source close to outfielder Matt Diaz confirmed to ESPN's Pedro Gomez that Diaz signed a two-year deal with the Pirates.
Jerry Crasnick is a senior writer for ESPN.com. Information from The Associated Press was used in this report.