In the United States, infection is now the most common cause of direct maternal mortality and the third leading cause overall after cardiovascular conditions and other pre-existing medical conditions. Nationally, there has been no improvement in the overall percentage of deaths from infection since 1987 when the CDC began maternal mortality surveillance, despite improvements in overall sepsis care for nonpregnant patients. The long-term goal is to reduce maternal morbidity and mortality from maternal sepsis. The central hypothesis is that though community leadership, addressing barriers, and intensive implementation of standardized pregnancy-adjusted screening, diagnosis, and treatment that maternal morbidity from infection and sepsis will decrease. The overall objectives in this application are to (i) identify patient-based and clinician-based barriers; (ii) refine sepsis screening in pregnancy; and (iii) implement a large-scale quality improvement collaborative. The central hypothesis will be tested by pursuing the following specific aims: UG3 phase 1) Develop and support a Maternal Sepsis Community Leadership Group of community representatives, patients, patient advocates, and survivors and family members of those who did not survive to inform and engage substantively throughout the study; 2A) Identify patient-based barriers to care for severe maternal infection and sepsis; 2B) Design strategies to implement evidence-based sepsis care interventions, specifically targeted to address and overcome barriers identified in Aims 2A and 2B; 3) Establish test characteristics of a pregnancy-adjusted intrapartum sepsis screen. Once barriers have been identified with strategies to overcome them and the sepsis screening, diagnosis, and treatment care practices have been adjusted based on qualitative and quantitative data it will be transitioned to the UH3 phase. UH3 Aim 1) Identify clinician-based barriers to implementation; 2C) Implement refined sepsis screening, diagnostic, and treatment care practices in California and Michigan and evaluate outcomes of maternal morbidity and mortality. The research proposed in this application is innovative because it is one of the first studies to co-lead a large-scale maternal initiative with representatives from the community, diversity, equity and inclusion (DEI), patient advocate representatives, and patients and families with lived experience with sepsis. This research is significant because it is expected that by identifying and addressing barriers to care and implementation through community, clinician, patient and DEI partnerships, this large-scale implementation initiative will serve as a national model to reduce maternal mortality and morbidity from sepsis, and potentially serve as a model to address other causes of mortality.