Yes, but it is not required. Collaborative Divorce is a specific system that helps parties reach resolution (i.e., it is not just working in a collaborative fashion). Attorneys are taught how to work in a specific team model during collaborative trainings, which is different than what that attorney may have learned in law school. The process is generally smoother and the results are generally better for both parties if both attorneys have that training, but it can still work if only one attorney is collaboratively-trained.