He committed to the Cyclones on February 6, 2007, but he struggled academically and was placed at Coffeyville Community College by Iowa State.

[4] In two seasons at Coffeyville Community College, Carpenter started every game at left tackle for the Red Ravens and earned All-Conference (KJCCC) honors twice.

[7] He made official visits to Texas Tech, Oklahoma, and Ole Miss, before eventually committing to Alabama and head coach Nick Saban.

[8] Carpenter faced the difficult task to replace All-American left tackle Andre Smith.

While analysts did not expect him to dominate as a run blocker like Smith, they saw him as "a rock in pass protection".

In the 2009 season, Carpenter was part of the undefeated Crimson Tide team that won the National Championship over the Texas Longhorns.

[10][11][12] Carpenter had a good post-season performance and, according to Sports Illustrated, went "from a third-round choice to a player who could be a surprise pick late in round one".

[27] In the 2014 season, Carpenter started all 13 games he appeared in and participated in the Seahawks making it to Super Bowl XLIX, where they lost to the New England Patriots by a score of 28–24.

[28][29] On March 10, 2015, Carpenter signed a four-year contract with the New York Jets worth $19.1 million.