A source told ESPN's Josina Anderson the deal is for two years and can be voided to one.
Patterson, 25, flourished early in his Vikings career but flailed in offensive coordinator Norv Turner's system for two seasons before rebounding in 2016 as Minnesota employed a short passing game to make quarterback Sam Bradford comfortable behind a leaky offensive line.
In 2015, Patterson's playing time was almost nil, which irked some team officials who felt the receiver wasn't being used enough. Heading into a contract year last season after the Vikings declined his fifth-year option, Patterson worked with a private coach in California and displayed better route-running skills during the offseason program.
He also embraced a role as a gunner on punt coverage, which showed the Vikings he'd be amenable to whatever role they asked him to play.
Patterson's opportunities on offense spiked after that, and he caught a career-high 52 passes for 453 yards in 2016, scoring a pair of touchdowns. He also again earned All-Pro honors as a kick returner, leading the NFL in return average for the third time in four years.
The Vikings sent four picks to the Patriots for the right to move back into the first round and select Patterson with the 29th overall pick in the 2013 NFL draft.
The University of Tennessee product led the NFL in kick returns as a rookie, earning All-Pro honors, and turned the league on its ear with a late-season flourish in 2013 that included seven rushing and receiving touchdowns as the Vikings found Patterson on screens, sweeps and handoffs out of the backfield.
When Turner arrived in 2014, the Vikings tried to use Patterson as a traditional receiver and cut his playing time when he didn't master the intricacies of route running in the NFL.
ESPN's Ben Goessling contributed to this report.