Mates of State are an American indie pop duo, active since 1997. The group is the husband-and-wife team of Kori Gardner (born June 16, 1974) (vocals, organ, synthesizer, piano, electric piano, and occasional guitar and drums) and Jason Hammel (born February 1, 1976) (vocals, drums, percussion, and occasional synthesizer). As of 2015, the duo has released four EPs and seven full-length, studio albums. Their most recent album, Mountaintops, was released on September 13, 2011.