No dollar figures were disclosed by the team but the St. Louis Post-Dispatch reported the six-year NFL veteran will make $10 million per season and $26 million in guaranteed salary.
"I'm entering my seventh season here and to know that I can finish my career here in St. Louis (is great)," Bulger told the newspaper. "I love living here."
Bulger had his best NFL season in 2006 with 24 touchdowns and 4,301 passing yards on 370 completions in 588 attempts and just eight interceptions.
The West Virginia product started all 16 games for the first time in his career.
He has a career completion percentage of 64.4 percent, having thrown for 16,233 yards with 95 touchdowns and 59 interceptions.