Over 30% of pregnant people have at least one chronic medical condition, and 20% have certain prenatal conditions (e.g., pregnancy-related hypertension, gestational diabetes) that increase the risk of chronic disease later in life. While patients with these conditions are typically highly engaged in prenatal care, they encounter a “postpartum cliff” in health system support after delivery; many receive no postpartum primary care at all despite having ongoing medical needs. At a time of increased stress, sleep deprivation, and competing demands, they must navigate administrative burdens in accessing primary care, often without scheduling assistance or any formal handoff between their obstetric and primary care clinician (PCP). These burdens may lead to avoided or delayed postpartum primary care, exacerbating health inequities that existed prenatally even for those fortunate enough to have a PCP. Given the many benefits of primary care, this lack of obstetric-to-primary care coordination represents a missed opportunity to increase primary care engagement and manage chronic conditions earlier in life. The primary objective is to increase postpartum primary care engagement, quality, and experience by strengthening obstetric-to-primary care coordination using a behavioral economics-informed intervention. The intervention, integrated into routine inpatient postpartum care, includes default PCP visit scheduling, tailored nudge messages to patients, ongoing care recommendations sent to the PCP, and a summary of recommendations after pregnancy given to the patient. Using a robust randomized controlled trial of 1,320 participants that is built off of the team’s pilot study, the proposed study will: (Aim 1) measure the intervention’s impact on postpartum primary care visit completion, sustained engagement, and disparities in these outcomes; (Aim 2) measure the intervention’s impact on high-value primary care service use; and (Aim 3) measure the intervention’s impact on patient experience, stress, and mental health. This project brings together a multi-disciplinary team and complementary skills in 1) health economics and behavior change, 2) obstetric and primary care research and clinical practice, and 3) the design, implementation, and analysis of RCTs to increase primary care engagement, a key priority in the context of declining and inequitable primary care use. This study responds to AHRQ’s Special Emphasis Notice expressing interest in health services research to advance primary care, including the interest in care coordination across providers with attention to health care disparities and patients with multimorbidity. It is also aligned with AHRQ’s interest in innovative approaches to study design, including the use of behavioral economics. The study will generate rigorous, actionable evidence to ensure primary care coordination becomes standard postpartum care practice and will provide insight into postpartum patients’ health care experiences. By targ...