Sources told ESPN on Wednesday that the deal is worth $30 million.
Touted for his play in coverage, Iloka, who turns 26 on March 31, became a valued piece of the Bengals' secondary the past four seasons.
The Bengals' starting deep safety since 2013, Iloka has tallied five interceptions and broke up 15 passes in that three-year stretch. Had it not been for a groin injury that made it tough for him to get into a rhythm last season, Iloka could have disrupted more passes. He missed four games in 2015.
Drafted in the fifth round in 2012, Iloka has exceeded many of the expectations that preceded him. He has been a valued starter and a hard hitter with 47 tackles last season.
ESPN's Adam Schefter, Adam Caplan and Coley Harvey contributed to this report.