Terms of the contracts were not announced.
Thomas played in Denver for the first nine years of his career from 2010-18.
The four-time Pro Bowler played 15 games split between the two teams last season, but tore his left Achilles tendon with Houston. Thomas was released by Houston on February 12, 2019. In his final eight games with the Broncos, Thomas had 36 receptions for 402 yards and three TDs.
That injury likely made Thomas a flawless low-risk, high-reward addition for the Patriots, as his rehab and uncertainty at 31 years old will nearly certainly keep the Patriots from any sort of significant financial commitment on this contract. He was a member of Denver's Super Bowl 50 championship season.
Thomas, 31, was acquired by the Texans from the Denver Broncos just before last season's trade deadline.
A 6-foot-3 threat, Thomas is coming off a 59-catch, 677-yard season split between the Denver Broncos and Houston Texans, and comes to the Patriots while recovering from a significant Achilles injury suffered in a December 23 game for the Texans. He was injured in the regular-season finale and was placed on injured reserve for the playoffs.
With 12 picks in the upcoming NFL Draft, there's a good chance the Patriots aren't done adding to their wide receiver depth chart ahead of the 2019 season. The Patriots enter the 2019 National Football League season without star tight end Rob Gronkowski - meaning more targets for the wide receivers.