Catcher J.T. Realmuto and the Philadelphia Phillies are in agreement on a five-year, $115.5 million contract, sources confirmed to ESPN's Jeff Passan.

The $23.1 million average annual value in Realmuto's deal is the highest for any catcher in Major League Baseball history. Realmuto also is just the third catcher in MLB history to sign a contract worth more than $100 million, joining Joe Mauer (eight-year, $184 million extension with the Minnesota Twins in 2010) and Buster Posey (nine-year, $167 million extension with the San Francisco Giants in 2013). Mauer previously held the record for highest average annual value, at $23 million, with his deal in 2010.

Realmuto is the first catcher to sign a contract worth over $100 million in free agency.

Realmuto, 29, continues to be one of the best all-around catchers in the majors, hitting .266 with 11 homers and 32 RBIs with the Phillies during the pandemic-shortened 2020 season. He did not accept an $18.9 million, one-year qualifying offer, instead seeking a longer-term deal on the free-agent market.

Since 2018, Realmuto leads all MLB catchers in WAR (10.1), RBIs (189) and stolen bases (16) and is second in slugging percentage (.489) and OPS (.825). His 57 home runs during that span ranks third among MLB catchers.

Defensively, he has 11 runs saved over the past two seasons, which ranks fourth among catchers who have played more than 1,000 innings.

Realmuto hit .275 with 25 homers and 83 RBIs while earning his second consecutive All-Star selection in 2019, leading the National League with 43 runners thrown out in his first season in Philadelphia. He was acquired in February 2019 in a deal that sent catcher Jorge Alfaro, two pitching prospects and international signing bonus pool money to the rebuilding Miami Marlins.

Realmuto lost his arbitration case with the Phillies before last season and received a raise from $6.05 million to $10 million; he had requested $12.4 million. He said he didn't harbor any resentment.

"I love this organization," he said. "They've been great to me and my family since I showed up. From top to bottom, they're good people and they care about baseball. That's important to me."

Realmuto, a career .278 hitter, was a first-time All-Star in his fourth season in 2018 when he hit .277 and set career highs with 21 homers, 74 RBIs and an OPS of .825.

The news of Realmuto's deal was first reported by MLB reporter Craig Mish.

ESPN Stats & Information contributed to this report.