There is evidence that social support is associated with enhanced resilience among grandparents parenting their grandchildren. One type of social support frequently accessed by grandparents is formal social support delivered by professionals in a variety of service settings. Unfortunately, grandparents experience a number of barriers to accessing formal support. In this chapter, we draw on existing literature and examples from our own empirical research to provide an ecological (Bronfenbrenner, 1979) conceptualization of best practices for providing formal support to custodial grandparents. Our recommendations move from proximal environments such as the grandparents' attitudes and beliefs about formal supports to more distal elements of the formal service environment such as program accessibility and the training and education of program staff. We also provide recommendations for macro issues related to program structure and availability. Together, these recommendations can help practitioners create welcoming service environments that are positioned to meet grandparents' varied needs.