Ian Rapoport of NFL Network reported the contract is for four years and $26 million. The Titans also announced the release of safety Johnathan Cyprien, who spent the last two seasons with the team.
Vaccaro, 28, signed a one-year, $1.5 million contract with the Titans in August. He recorded 58 tackles and one interception while appearing in 13 games.
"Kenny came in and played really good football for us," Titans general manager Jon Robinson said at the combine. "We are kind of working through several things now with him, with that position group as a whole. There's some guys in free agency, Kenny being a primary target. We'll kind of see how that ... plays out."
Vaccaro spent his first five seasons with the New Orleans Saints, producing at an inconsistent level. His play seemed to vary from year to year, he looked at times like a solid long-term starter and others like one of the worst starting safeties in football.
The 2017 season was particularly rough for Vaccaro, who struggled to play through wrist and groin injuries. The result was a tepid free-agent market that saw him languish in free agency deep into the summer. Tennessee only signed Vaccaro after Cyprien suffered a season-ending torn ACL.
Cyprien was due a $5.5 million base salary in 2019. He will hit a market that's flush with safety talent and may be in the same position as Vaccaro from a year ago, searching for a one-year "prove it" deal before hitting the open market.
Vaccaro's new contract comes with enough guarantees that he should be with the Titans through at least the 2020 season, barring a cataclysmic falling off.