Trout has now committed to the Angels for a bit longer than that, and the Angels have commited a bit more money to him.
The two sides have agreed to a six-year, $144.5 million contract that will start after the 2014 season.
Trout finished second in the American League MVP voting to Miguel Cabrera in each of his first two seasons, and was the 2012 AL rookie of the year.
Trout's deal comes on the heels of Cabrera signing an eight-year $248 million extension, which leaves his total remaining contract value at $292 million.
The average $24 million salary for Trout over the course of the six years would rank third in the MLB this season, just behind the $25 million Cliff Lee and Ryan Howard are making from the Philadelphia Phillies.