Dr. Shen has been selected to receive a MERIT Award (R37) from the NCI for her outstanding merit on an R01 application as an early stage investigator. Multiple interventions have been developed to improve advance care planning (ACP), most of which focus on patient education and decision-making aides but neglect the social features of ACP. This project will take a new approach to ACP by addressing the prevalent patient-reported need to incorporate their social network (typically, but not exclusively, family) into the ACP process. This study will aim to develop and test our mobile health (mHealth) application, PACT (Planning Advance Care Together). PACT is grounded in decision-making research that indicates individuals often make decisions with the input of social “informants” or influences. PACT will utilize mHealth technology to provide empirically based features to meet patients’ reported need to incorporate loved ones into the ACP decision-making process and thus bolster their social networks. In short, PACT will allow patients to design the social environment of their ACP process, with the intended goal of receiving the support they need and ultimately improving their engagement in ACP and receipt of value-consistent end-of-life care.