The ROSE Program (Reach Out, Stay Strong, Essentials for mothers of newborns) is a small-group intervention to prevent PPD that is delivered during pregnancy in outpatient prenatal settings. ROSE is the only PPD preventative intervention that (1) has been found to significantly reduce cases of PPD in multiple randomized trials, and (2) has been tested in community prenatal settings with racially and ethnically diverse low income pregnant women. ROSE consists of four 90-minute group sessions and a 50-minute individual booster session after delivery. Requests for ROSE training in Philadelphia and nationwide in Japan, and recent policy changes supporting payment for comprehensive perinatal services (including behavioral health care) to underserved populations all suggest a context ripe for embedding ROSE in prenatal clinics long-term. Given the need for ROI studies about sustainment efforts and that ROSE is well-positioned for implementation and sustainment research, we propose a Sequential Multiple Assignment Randomized (SMART) Trial of the effectiveness and cost-effectiveness of a stepwise approach to sustainment of ROSE in 90 outpatient clinics providing prenatal care to pregnant women on public assistance in 6 U.S. states (MI, NY, RI, PA, MA, FL). Our conceptual framework comes from RE-AIM and a review on sustainment by Co-I Wiltsey-Stirman,3 with sustainment strategies based on the Replicating Effective Programs (REP) framework. All clinics will receive enhanced implementation as usual (EIAU; initial training + tools for sustainment). Clinics will be assessed using surveys and qualitative interviews 9 times over 2.5 years after receiving EIAU. Clinics at risk for failure to sustain operationally (defined as no ROSE intervention in 3 months and none planned) and/or clinically (defined as low fidelity to ROSE core elements) will be randomized to receive additional sustainment support for up to 18 months after baseline. At the first time period at which a clinic is determined to be at risk (i.e., at 3, 6, 9, 12, or 15 months), that clinic will be randomized to receive either: (1) no additional implementation support (EIAU only), or (2) EIAU plus low-intensity (every 3 months) coaching and feedback (LICF). If clinics receiving LICF are still at risk at subsequent monitoring periods, they will be randomized to (1) EIAU + LICF only, or (2) EIAU + LICF + high-intensity (monthly) coaching and feedback (HICF). Additional study follow-up interviews will occur at 18, 24, and 30 months, but no implementation intervention will occur after 18 months. We will assess costs and benefits of sustainment strategies. Aims are to: