PROJECT SUMMARY The hemoglobinopathy newborn screen (NBS) performed on all neonates in the U.S. allows for early life-sav- ing medical care for infants with sickle cell disease (SCD). Because of its detection method, the NBS inci- dentally reveals hemoglobinopathy carrier states including sickle cell trait (SCT). Such findings present a unique ethical challenge: Whether to disclose the newborn’s carrier status and, by default, the carrier status of one parent. In an effort to uphold the rights of the newborn and parent to their medical data (i.e., NBS result, SCT status) and preserve autonomy in medical decision making, pediatric and genetic society guidelines rec- ommend disclosure and documentation of NBS SCT carrier results during infancy. Despite this ethical impera- tive, a large guideline-to-practice gap exists: SCT carrier status is grossly under-documented in the pediatric electronic health record (EHR) and few adults report knowing their SCT status despite universal screening. Failure to disclose SCT carrier status obstructs an individual’s ability to make informed reproductive decisions. Additionally, lack of documentation of SCT carrier status hampers physicians’ and researchers’ abilities to identify the growing list of medical complications attributed to SCT. We propose to use implementation science methods to close this practice gap for the nearly 3 million carriers of SCT in the US, most of whom are Black or Hispanic. Using mixed method qualitative and quantitative methods we will identify the barriers, facilitators, and implementation strategies necessary to increase: 1) the documentation of NBS and SCT carrier status within the EHR; 2) disclosure of results to caregivers during infancy; and, 3) discussions about reproduction implica- tions with adolescent SCT carriers. We will develop and pilot test a SCT Documentation and Disclosure Toolkit for use by primary care physicians during infancy and an SCT Discussion Toolkit for use with adolescents. Ac- curate documentation and disclosure of NBS results and SCT carrier status is critical to the responsible and ethical care of patients with SCT; will improve health outcomes; and will reduce inequities in care.