The deal contains a $5,625,000 team option for 2020, and the option price could escalate based on games in 2019: $2,725,000 for 50, $2,825,000 for 60 and $2,925,000 for 68.
The agreement is at the midpoint of the $1.4 million the 28-year-old right-hander asked for and the $1.65 million he had been offered.
Devenski would earn $100,000 for winning a Cy Young Award, $75,000 for finishing second in the voting and $50,000 for third. He also would get $75,000 if he is World Series MVP, and $50,000 each for making the All-Star team, winning League Championship Series MVP or earning a Gold Glove.
Devenski was 2/3 with a 4.18 ERA last year, striking out 51 and walking 13 in 47 1/3 innings. He was sidelined between July 27 and Aug. 30 because of left hamstring tightness, the first time in his big league career he was on the disabled list.
He had a $599,200 salary last season and was eligible for arbitration for the first time.
Devenski was 8-5 with a 2.68 ERA in 2017, striking out 100 and walking 26 in 80 2/3 innings.
Astros starter Gerrit Cole remains scheduled for a hearing. He has asked for a raise from $6.75 million to $13.5 million and was offered $11,425,000.