Last April, Zuerlein was coming off a down year and had to settle for a one-year deal. He converted only 66.7 percent of his field goal attempts in 2015, tied for last among those with at least 15 tries. But he improved that percentage to 86.4 in 2016 -- ranked 10th -- and earned more long-term security.
Rams punter Johnny Hekker voiced his appreciation on Twitter.
Zuerlein, 29, will be reunited with Hekker and special-teams coordinator John Fassel, one of only three holdovers from Jeff Fisher's coaching staff.
Zuerlein's greatest asset is his leg strength. He has converted two field goals of 60 or more yards and has made 18 50-plus-yard field goals over his five-year career, ninth most in the NFL. His career field goal percentage of 79.4 ranks 45th among 56 qualified kickers since 2012, but his inordinate amount of long attempts has affected that rate.
This past season, Zuerlein missed only one of his 18 attempts within 50 yards.