Financial terms were not disclosed.
Maier is the longest-tenured member on the Royals' 40-man roster and will start his 10th season in the organization. He was selected by the club with the 30th overall pick of the 2003 draft.
The 29-year-old Michigan native appeared in just 44 games last season and batted only .232 with seven runs batted in. He is a career .253 hitter with eight homers and 86 runs batted in over 327 games in parts of five major league seasons.