Jarwin's deal has a base value of $22 million, includes $9.25 million guaranteed and maxes out at $24.25 million, the source told ESPN's Field Yates.
Jarwin, who signed with the Cowboys as an undrafted free agent in 2017, is in line for a larger role with the offense in 2020, though Jason Witten could still return for a 17th season. The Cowboys were expected to put a second-round tender on Jarwin but wanted to sign him to a deal beyond this season.
Jarwin, 25, caught 31 passes for 365 yards and three touchdowns while starting seven games and playing 38.6% of the snaps in 2019. In 2018, he caught 27 passes for 307 yards and three touchdowns while starting four of 16 games.
He has shown the ability to make big plays, with a 42-yard touchdown catch last season, but needs to continue to develop as a blocker.
Witten, the franchise leader in games played, catches and receiving yards, said earlier in the offseason that he would like to return to the Cowboys but is open to playing elsewhere. Speaking at the NFL scouting combine, owner and general manager Jerry Jones said he hoped Witten would not play in another uniform and that he would like Witten to return provided he accepts a lesser role than what he had in 2019.