Janikowski will receive $19 million over the life of the contract, with $8 million guaranteed in the first two years. His yearly salary of $3.8 million makes him the highest paid kicker in the league.
Janikowski is the team's all-time leading scorer with 1,318 points.
The 13-year veteran has spent every season in his career with the Raiders since being drafted out Florida State in the first round in 2000.
Last season, Janikowski scored 118 points, making it the third straight season he scored more than 100 points. He made 31-for-34 on field-goal attempts in 2012, with his only misses coming on 51-, 61- and 64-yard attempts. MACK: Fantasy football 2013 kicker position primer