Patients with severe mental illness often lack care coordination between primary care and mental health providers. Siloed patient care across separate health care systems can negatively impact quality and safety of patient care. The purpose of the project discussed in this article is to effectively engage stakeholders from separate primary care and mental health organizations to develop an ideal cross-organization communication system to improve metabolic monitoring for their comanaged patients prescribed second-generation antipsychotics (SGAs).The mixed method approach of group concept mapping was used to engage stakeholders across a nonaffiliated primary care clinic and a community mental health organization over the time period of March 2018 through May 2018.Three important domains in communication were identified: (1) process/workflow, (2) advocacy, and (3) a patient-centered focus. Seven high priority/easier to implement brainstormed items were identified and resulted in practice changes across both organizations, including developing a standard release of information, identifying a point person from each clinic focused on cross-organization care coordination, endorsing an SGA monitoring protocol across organizations, agreeing that metabolic monitoring of SGAs will be the responsibility of the primary care clinicians, beginning monthly medication reconciliation and cross-organization care conferences, developing standard electronic health record documentation, and providing education.Care coordination across all health systems is critical to optimize patient care for chronic medical and psychiatric conditions. Group concept mapping provides a strategic process to allow shared decision-making among stakeholders to take steps toward solving more complex systematic problems such as poor electronic health record interoperability across health systems.