Financial terms were not revealed, but sources confirmed the 28-year-old will make $21 million: $6 million in 2014, $7 million in '15 and $8 million in '16.
Per team policy, the contract does not include a no-trade clause.
The Saltalamacchia signing came at a time when the Marlins are finalizing a one-year deal with free agent Rafael Furcal, who will switch from shortstop to play second base. Furcal, 36, missed all of last season with the Cardinals due to Tommy John surgery on his right elbow.
Saltalamacchia reached agreement early Tuesday night, and passing the physical was the final step. That came on Thursday.
In many ways, the matchup is a natural fit.
The 6-foot-4, 235-pound catcher is a South Florida native, so playing in Miami will be a homecoming. Saltalamacchia attended Royal Palm Beach High School, whis is in the same county as Miami's Spring Training home in Jupiter, Fla.
For the Marlins, Saltalamacchia fills a need for a more offensive-minded catcher. He is a switch-hitter coming off a strong season for the World Series-champion Red Sox, for whom he batted .273 with 14 homers and 65 RBIs.
Saltalamacchia is a career .246 hitter with 78 homers and 275 RBIs in parts of seven big league seasons. But his production especially picked up after he joined Boston in 2010. He belted a career-high 25 homers in 2012.
In each of the past two seasons, Saltalamacchia has appeared in 121 games. His arrival means that Jeff Mathis will become the backup behind the plate. Rob Brantly, Miami's Opening Day catcher last season, likely will open at Triple-A New Orleans.
The fact that the Marlins dipped into the free agent market for a catcher is mildly surprising, because payroll is a concern. They are operating within modest parameters -- payroll projections are estimated to be about $45 million. Plus, in recent years, the organization hasn't had much success signing players to multiyear, free-agent contracts.
In 2012, for instance, the front office went on an unprecedented spending spree, bumping payroll to $100 million in the inaugural season at Marlins Park. High-priced free agents Jose Reyes, Mark Buehrle and Heath Bell each signed multiyear contracts. All three were traded after one disappointing season.
Many in the industry wondered if the Marlins could convince an established free agent to sign a multiyear deal. Saltalamacchia showed they can, if the price and opportunity are right.
Coming off a World Series championship season, Saltalamacchia also becomes an immediate leader and veteran presence on a youthful Miami squad. The Marlins were 62-100 with a core of youthful players in 2013. Signing Saltalamacchia is a signal that the Marlins are looking to keep building, instead of subtracting their core players.
Although the organization has struggled on the field in recent years, their roster is filled with promising talent. But much of it is unproven.
Strong pitching is one reason the Marlins are optimistic they can turn their fortunes around in the next couple of seasons. Despite finishing with 100 losses, the Marlins sported a franchise-best 3.71 ERA in 2013.
The rotation is headed by Jose Fernandez, the 21-year-old sensation who was the National League Rookie of the Year. Nathan Eovaldi is a hard-throwing right-hander, and his fastball reached 100 mph in '13. Henderson Alvarez, projected to be the No. 3 starter, no-hit the Tigers in the regular-season finale.
The bullpen features closer Steve Cishek and some other quality arms like those of Mike Dunn and A.J. Ramos.
Run production is Miami's biggest need. With Saltalamacchia in the fold, the Marlins are looking to add more parts around slugger Giancarlo Stanton, who is not available on the trade front.
Saltalamacchia should be another middle-of-the-lineup presence, but he isn't the only piece the club is looking to add this offseason. Furcal's deal is expected to be finalized after he completes his physical.
The Marlins headed into the Winter Meetings on Monday seeking a third baseman. But if something makes sense, they could explore options for either more power or speed.
A compensatory first-round Draft pick of the Braves in 2003, Saltalamacchia made his Major League debut with Atlanta in 2007. He played three seasons for the Rangers before being dealt to the Red Sox in 2010.