Hamels and the Phillies avoid an arbitration hearing with the deal.
The people spoke to The Associated Press on the condition of anonymity because an official announcement hasn't been made. A news conference is planned for Sunday.
Hamels established himself as a true ace in the postseason, going 4-0 with an 1.80 ERA as the Phillies claimed their first championship since 1980. He won the first game in three playoff series and also captured the MVP award in the National League championship series against the Dodgers.
Hamels went 14-10 with a 3.09 ERA during the regular season and was eligible for arbitration for the first time.
Hamels, who had been injury prone early in his career, showed his durability by making 33 starts and pitching a career-high 227 1-3 innings. He finished with 196 strikeouts and 53 walks.
Hamels was a first-round pick in 2002. He made his major league debut in 2006 and led the team with 15 wins in his first full season in 2007.
He has one of the best changeups in the league and anchors a strong rotation that includes Brett Myers, Joe Blanton and Jamie Moyer, who has played an important role in his development.
In October, when the Phillies celebrated the city's first major sports championship in 25 years, Hamels told fans he wanted more chances to ride down Broad Street in a parade "again and again and again."
Now, it looks as if he'll have that chance for the next three seasons.
Six Phillies remain in arbitration: First baseman Ryan Howard, outfielders Shane Victorino and Jayson Werth; and right-handers Blanton, Chad Durbin and Ryan Madson. Players who don't settle by Tuesday will exchange figures with the club. Hearings take place next month.
