He was selected by the Pittsburgh Pirates in the 9th round of the 2010 Major League Baseball draft and made his MLB debut for them in 2013.

[1][2][3] The Pittsburgh Pirates selected Cumpton in the ninth round of the 2010 Major League Baseball Draft.

[4] In his major league debut that day, Cumpton pitched five innings (facing three batters in the sixth), allowing three earned runs and seven hits in a no decision against the Los Angeles Dodgers.

Cumpton, ultimately, had his worst start to date, allowing ten earned runs in 3 2/3 innings pitched.

[7] On January 10, 2018, Cumpton signed a minor league contract that included an invite to spring training with the Texas Rangers.

[9] On April 18, 2018, Cumpton signed with the Southern Maryland Blue Crabs of the Atlantic League of Professional Baseball.

On July 5, 2018, Cumpton signed a minor league contract with the Toronto Blue Jays and was assigned to the Triple-A Buffalo Bisons.

[11] On April 25, 2019, Cumpton signed with the Southern Maryland Blue Crabs of the Atlantic League of Professional Baseball.

On June 14, 2021, Cumpton was traded to the Guerreros de Oaxaca of the Mexican League in exchange for P Héctor Hernández.