Sumlin, 48, will be paid $3.1 million a year, The Dallas Morning News reported. Sumlin's previous deal with Texas A&M paid him $2 million.
The Morning News, which posted the contract on its website, said Sumlin, effective April 1, will receive $500,000 in salary with supplemental payments starting at $2.6 million in 2013, going to $2.725 million in 2015 and being reduced to $2.3 million in 2017.
The overall package reportedly includes bonuses for achievements such as winning the SEC title, bowl games appearances and $400,000 should the Aggies win the college football national championship.
Sumlin built a 35-17 record in four seasons at Houston, his first head coaching position, before joining Texas A&M before last season.
The Aggies' 11-2 2012 season included a Cotton Bowl victory while quarterback Johnny Manziel won the Heisman Trophy and offensive tackle Luke Joeckel was awarded the Outland Trophy.