In the US, high rates of maternal morbidity are urgent public health concerns. Social risk factors, such as low socioeconomic status and limited access to care, critically shape perinatal outcomes, resulting in greater risk of adverse maternal and neonatal health outcomes for low-income women. High-quality antenatal care supports optimal health, yet typically fails to meet the needs of some populations, including those with lower incomes. Improving the health of pregnant people in a patient-centered manner requires innovative models of care delivery across the spectrum of maternal care. One strategy is patient navigation (PN), a longitudinal, barrier-focused, patient-centered intervention that offers support for health services. Although antenatal care is an ideal setting for PN, the benefits of antenatal PN for overall maternal and perinatal health have not been rigorously evaluated in randomized trials. This proposal aims to test the efficacy of an innovative antenatal care PN model that extends and expands care for low-income pregnant women via the Partnering with Antenatal Navigators to Transform Health in Pregnancy (PATH) Trial. We will randomize 550 nulliparous pregnant women with low income to receive PN via PATH versus usual antenatal care. Participants randomized to receive PATH will receive intensive, individualized PN services throughout pregnancy. As a multilevel, multidomain, health intervention, PATH is grounded in understanding and addressing approaches to promote self-efficacy, enhance access, support communication, and sustain healthcare engagement. All participants will undergo surveys, interviews, and medical record reviews at 5 study visits from enrollment (<20 weeks of gestation) through 9 months postpartum. Aim 1 will evaluate whether PATH, compared to usual care, improves a composite of maternal adverse outcomes (hypertensive disorders, preterm birth, postpartum hemorrhage, severe maternal morbidity, mortality) and (Sub-Aim 1) healthcare utilization. Aim 2 will evaluate whether PATH, compared to usual care, improves a composite of perinatal adverse outcomes (NICU, low birthweight, small- and large-for-gestational age, perinatal death) and (Sub-Aim 2) healthcare utilization. Exploratory Aims 1 and 2 will evaluate whether PATH’s efficacy varies by different demographic factors (e.g., age). Aim 3 will evaluate patient, clinician, navigator, and health system experiences with PATH, which will be guided by implementation science principles and accomplished via serial collection of patient-reported outcomes, individual interviews, and process mapping exercises. The PATH Trial will fill a significant evidence gap by demonstrating whether antenatal PN among low-income pregnant women, who are disproportionately at risk for adverse outcomes, is an effective strategy to improve perinatal health. PATH represents a critical step in understanding how to improve maternal health, thus achieving an NIH goal.