Maualuga, 26, had 122 tackles, including a sack, last season. Only Vontaze Burfict, with 127 tackles, had more stops for the Bengals in 2012.
The Cincinnati Enquirer said the deal will pay Maualuga $6.5 million over the next two seasons.
"Rey has been a fine young player for us, and he continues to grow on and off the field," said Bengals Coach Marvin Lewis. "He is passionate about becoming a great player and we're excited to have him back as we work with these signings to keep our defense together."
The Bengals were sixth in the NFL in yards allowed last season and eighth in points allowed.
Maualuga was the 38th overall selection in the 2009 NFL draft. In 60 NFL games over four seasons, he has 348 tackles with three sacks and three interceptions.