The home was broken into between Friday and Monday when no one was home, said police Sgt. Lee Sands. A person arriving at the house Monday morning discovered the crime and called police, he said.
Police would only say an unspecified amount of money was taken and they had no immediate suspects.
The house is not the couple's principal home, said Paul Freundlich, Hill's publicist. The singers, who live in Nashville, Tenn., were not in Los Angeles for Sunday night's Grammy Awards, he said.
McGraw and Hill, both 39, are among the biggest stars in country music, separately and as a duo. Between them, they have won numerous honors including Grammys, American Music Awards, Country Music Association Awards and Academy of Country Music Awards.