Background: Caregivers are decision stakeholders; yet, few interventions have been developed to help patients and caregivers collaborate on advance care planning (ACP). Objective: To evaluate a theory-based ACP pilot intervention, Deciding Together, to improve decisional quality, readiness, collaboration, and concordance in ACP decisions for older adult home health (HH) patients and caregivers. Design: A one-group, pre- and posttest study using matched questionnaires was conducted.