Research findings have consistently demonstrated that women living with HIV in the United States and globally experience declines in medication adherence and retention in care after giving birth. A number of studies have identified factors associated with postpartum retention in care, but the evidence base for interventions to address the problem and close this gap in the HIV care continuum is limited. Furthermore, the majority of studies have been conducted in low-resource or moderate-resource countries and may be less applicable or require adaptation for use in high resource countries. In the United States, up to two-thirds of women drop out of care after delivery and are unable to maintain or achieve viral suppression postpartum, at a time when maternal and pediatric health are closely linked. We conducted a critical review of the literature to identify existing gaps regarding maternal retention in the United States and conceptualize the problem through the lens of the integrated and ecological models of health behavior. This review describes existing barriers and facilitators to retention in HIV care postpartum from published studies and suggests steps that can be taken, using a multilevel approach, to improve maternal retention. We propose five core action steps related to increasing awareness of the problem of poor postpartum retention, addressing needs for improved care coordination and case management, and using novel approaches to adapt and implement peer support and technology-based interventions to improve postpartum retention and clinical outcomes of women living with HIV.