This article focuses on negligence allegations associated with treating atrial fibrillation during transitions in and out of the hospital. A common thread among these claims was disagreement about who on the patient healthcare team was responsible for prescribing and managing anticoagulation therapy. Most involved multiple defendants, including cardiologists, emergency department physicians, hospitalists, the patient’s primary care physician, and various staff members in both the hospital and office setting. In many of these claims, multiple members of the patient’s healthcare team were deemed responsible for contributing to the error(s) that caused the injury. This article provides strategies to improve communication and teamwork, with the objective of reducing patient injuries associated with the treatment of atrial fibrillation during transitions in and out of the hospital.