The couple, who are the parents of pop star Miley Cyrus, have been married more than 19 years. Billy Ray also filed for divorce in 2011, then withdrew the papers after an apparent reconciliation.
"I spoke to Tish and she told me they both woke up and realized they love each other and decided they want to stay together," family friend Ken Baker told E! News.
"They recently went into couples therapy, something they hadn't done in 22 years of being together, and it's brought them closer together and really opened up their communication in amazing ways," Baker said. "She also said marriage can be really hard, especially after 22 years of being in the entertainment business, and admitted they've had rough times. But they both realized they didn't want to be another statistic and want to make it work. They went into the therapy with the goal of divorcing in a way that was healthy for the children, but ended up coming out of it with the realization that they in fact want to stay together. Tish sounds happy and energized about having this fresh start."
Tish posted a photo of herself with Billy Ray on Instagram Sunday night accompanied by the caption, "Date Night."