In recent years, family courts have made increasing use of advisors and/or advocates (e.g., forensic psychologists, social workers, best interest attorneys, guardian ad litems, etc.) in determining outcomes in child custody disputes. Evidence suggests that recommendations from advisors and/or advocates carry considerable weight in judges’ custody determinations. As a result, the present study examined processes and mechanisms utilized by a custody advocacy program in formulating, determining, and operationalizing the best interests of children, as well as barriers and challenges experienced in doing so. The Custody Advocacy Program (CAP) examined in this study utilizes a unique structured model (within the context of custody advocacy and legal representation), consisting of a staff attorney, volunteer attorney, and a custody advocate (collectively, the "best interest team"). Given the exploratory nature of this study, an ethnography-inspired approach was utilized, with data drawn from interviews and systematic observations (of a CAP staff meeting and a trial). Interviews were transcribed and analyzed using a constant comparative method. Findings indicated that the structural model of CAP yielded several benefits including a representation of a diverse set of perspectives when determining custody recommendations, reduced personal biases, and specialized legal knowledge. Moreover, the study revealed how staff attorneys interviewed for the purposes of the study defined the concept of "best interests," which consisted of children having a relationship with both parents, safety, health adjustment, satisfactory mental and physical health, and legal custody. Study findings also underscored challenges in custody advocacy, such as families experiencing barriers in accessing recommended services, family noncompliance to investigations and/or recommendations, and difficulty assigning weights to factors in cases when determining custody arrangements. Overall, study findings suggest that a structured model like CAP may be beneficial in improving how children’s best interests are represented and advocated for in high-conflict custody cases. Implications from this study include a recommendation for a judicial and legislative response that ensures that all aspects of best interests are addressed in state statutes.