Brantley Gilbert and Jana Kramer have split.

According to a source, the engaged couple blame their careers for the break-up. The insider tells People magazine, "They are both so busy right now. They are both on the road and have to spend a lot of time apart, which isn't ideal for any couple, let alone a couple trying to plan a wedding." 

The source also says that they were happy together, but know the split is for the best.