The 32-year-old former 'One Tree Hill' star and the tech engineer called it quits back in February, according to Us Weekly.
An insider claims they "still really care a lot about each other but it was impossible to retain a romantic relationship with the careers they have."
Bush and Fredinburg first went public with their relationship last year when they were spotted cuddling and holding hands at the Coachella Music Festival in California.
Earlier this year, Fredinburg suffered a mountain climbing scare after he narrowly avoided a deadly avalanche in Mount Everest.