The 27-year-old is guaranteed $13,925,000 under Friday's deal. He keeps the $2,425,000 salary he agreed to in January under a one-year agreement, and the sides added guaranteed years at $4.4 million for 2011 and $6.5 million for 2012.
Texas gets a $9.25 million option for 2013 with a $600,000 buyout.
Feldman started last season as the long reliever in the Texas bullpen and was inserted into the rotation on April 25. He went 17-8 with a 4.08 ERA in 31 starts and three relief appearances.