Purpose Providing long-acting reversible contraception (LARC) in the immediate postpartum period is an evidence-based strategy for expanding women's access to highly effective contraception and for reducing unintended and rapid repeat pregnancy. The purpose of this article is to demonstrate the application of implementation science methodology to study the complexities of rolling-out policies that promote immediate postpartum LARC use across states. Description The Immediate Postpartum LARC Learning Community, sponsored by the Association of State and Territorial Health Officials (ASTHO), is made up of multi-disciplinary, multi-agency teams from 13 early-adopting states with Medicaid reimbursement policies promoting immediate postpartum LARC. Partners include federal agencies and maternal and child health organizations. The Learning Community discussed barriers, opportunities, strategies, and promising practices at an in-person meeting. Implementation science theory and methods, including the Consolidated Framework for Implementation Research (CFIR), and a recent compilation of implementation strategies, provide useful tools for studying the complexities of implementing immediate postpartum LARC policies in birthing facilities across early adopting states. Assessment To demonstrate the utility of this framework for guiding the expansion of immediate postpartum LARC policies, illustrative examples of barriers and strategies discussed during the in-person ASTHO Learning Community meeting are organized by the five CFIR domains-intervention characteristics, outer setting, inner setting, characteristics of the individuals involved, and process. Conclusion States considering adopting policies can learn from ASTHO's Immediate Postpartum LARC Learning Community. Applying implementation science principles may lead to more effective statewide scale-up of immediate postpartum LARC and other evidence-based strategies to improve women and children's health.