The 29 year-old lefthander is coming off a season in which he went 11-7 with a career low 3.15 ERA (70 ER/200 IP) and 1.05 WHIP. He also set a career high with 246 strikeouts, good for third in the National League.
Like Stephen Strasburg, Corbin had Tommy John surgery earlier in his career, missing the entire 2014 season. Last year was the first time he had cleared 200 innings since 2013, before his injury.
Corbin joins an already pricey rotation that includes both Max Scherzer ($210 million total contract value) and Strasburg ($175 million). While the deal does not necessarily preclude the team re-signing free agent outfielder Bryce Harper, the Nationals have now devoted a significant portion of their payroll elsewhere, especially if they plan to try to get back below the luxury tax line for the 2019 season.