A source told ESPN that the contract is for $16 million and includes a vesting option for the 2020 season worth $10 million. The option will vest if Cashner pitches 340 innings combined in 2018-19. If he throws 360 innings combined in 2018-2019, it becomes a player option.
"I do know that they need some starting pitching, and here it is, show up every day and whoever I can help out, help out and my job is to come here and pitch and win,'' Cashner said.
Cashner was at the Orioles' spring training facility, and was due to head to his Texas home for a few days before returning on Sunday when Baltimore's full squad is required to report. He'll probably work out with the team for the first time Monday.
He has little experience against the Orioles but said he was excited to join the team.
"It's a lineup you can't really make a lot of mistakes against,'' Cashner said. "It's a lot of power in there, and I got to pitch [for] San Diego one year in Baltimore. Really cool stadium, really neat, a lot of history. It's one of my favorite places to pitch, so I'm looking forward to making that my home [stadium] every night.''
Manager Buck Showalter said Cashner would be an ideal addition to the club.
"He's a veteran starter. That's a good deal for both us and him,'' Showalter said. "He's a guy who's pitched well in the American League. That's something that I think played in his favor."
Cashner, 31, has pitched seven seasons in the big leagues, most recently in Texas. He was 11-11 with a 3.40 ERA in 28 starts for the Rangers in 2017 after missing most of spring training and the start of the season because of soreness in his right biceps.
Cashner, a Texas native who was a first-round draft pick out of TCU in 2008, was drafted 19th overall by the Chicago Cubs. He made his major league debut two years later with 53 appearances for Chicago. The Cubs traded him to San Diego after the 2011 season, in the deal that sent first baseman Anthony Rizzo to Chicago, and Cashner eventually became a starter for the Padres.
The news of Cashner's agreement was first reported by MASN Sports.
ESPN's Jerry Crasnick and The Associated Press contributed to this report.