The move sets him up for a reunion with Brian Flores, who worked as the Patriots defensive play-caller in 2018 before taking the head coaching job in Miami in 2019.
McCourty, who will turn 34 years old in August, is entering his 13th NFL season. He played with the Tennessee Titans (2009-2016), Cleveland Browns (2017) and New England Patriots (2018-2020) before joining the Dolphins.
The Rutgers alum won the Super Bowl with the 2018 Patriots, starting in the secondary alongside his twin brother, Devin McCourty.
For his career, Jason McCourty has recorded 18 interceptions, 723 tackles, 106 pass breakups and four touchdowns.
He's primarily been a starter since the 2011 season, when he was the Titans' left corner. Last year, McCourty played 16 games (11 starts), registering 42 tackles and three pass breakups.
Pro Football Focus gave McCourty the following write-up when discussing his 2020 season.
"After an incredible start to his time in New England, Jason McCourty has seen his role reduced, but he still technically started 11 games in 2020 and played a versatile part within the New England defense, lining up at safety or in the slot on occasion in addition to his usual spot out wide. He is now 33 years old and coming off his lowest PFF coverage grade (51.8) since 2015. This season, he allowed a 135.0 passer rating when targeted. His versatility is useful, but McCourty isn't transforming anybody's secondary."
The 2020 season was a bit of a down year for McCourty, but it would have been hard to replicate his excellent 2019 campaign. Per Pro Football Reference, opposing quarterbacks completed just 48.2 percent of passes in his direction for 4.8 yards per target.
Now, he'll slot into a secondary that also boasts star Xavien Howard, who earned a first-team All-Pro nod in 2020.
McCourty is still a capable defensive back who can provide depth at minimum, and he'll look to continue his stellar career in Miami.