Simms is scheduled to become a free agent in March. It was uncertain whether the Bucs would make an effort to keep the quarterback, whose season ended Sept. 24 when he had his spleen removed after being injured in a loss to the Panthers.
Simms could not be reached for comment. Simms' agent, Tom Condon, said: "I don't comment on negotiations."
A Buccaneers source said the two-year offer was "substantial enough" to get Simms' attention and that the team is expecting a healthy dialogue with Simms before the end of the season.