The deal announced Saturday is reportedly worth $52 million, with $27 million guaranteed. The 27-year-old Jeffery signed a one-year deal with the Eagles in free agency in March after playing for the Chicago Bears his first five seasons.
"I love it here," Jeffery said in a statement issued by the team. "I'm blessed to have the opportunity to play for this organization and for these fans. Everyone has welcomed me with open arms and now I'm looking forward to being here for a long time. We have a great group here and I'm excited to be a part of it."
The Eagles lead the NFL with a 10-1 record and play at Seattle (7-4) on Sunday.
Jeffery is tied for fifth in the NFL with seven touchdown catches. He is second on the team with 43 receptions and 619 yards receiving.
"Alshon has been a tremendous addition to this organization on and off the field," the team said in a statement. "We place a priority on making sure we are able to build the team around quality players like Alshon who embrace this team and this city the way he has. We are excited about his future here."
Jeffery has 347 receptions for 5,168 yards and 33 touchdowns in 74 career games.
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