Patrick Dempsey and his estranged wife Jillian are "working on their relationship" nearly 11 months after filing for divorce, a source tells PEOPLE.
The couple, who share three children – Tallula, 13, and twins Sullivan and Darby, 8 – announced their split in January.
Jillian and Patrick, 49, were married for 15 years before their early 2015 split.
"[The split] was a long time coming," a source close to the couple told PEOPLE at the time. "They were never going to make it work, but they tried." Adds a family source, "They have had disagreements for a long time."
Then, in April, shortly after the onscreen death of his longtime Grey's Anatomy character, the couple prepared to list their $14.5 million Frank Gehry-designed Malibu estate for sale.