Mothers with intellectual and developmental disabilities (IDD) are vulnerable to perinatal complications and adverse outcomes. Their vulnerabilities may also be exacerbated by co-occurring behavioral health (BH) conditions. Their wellbeing may be compromised by a lack of tailored treatments or by treatments and services that are inaccessible, irrelevant, and/or ineffective. A five-session virtual Ideas Lab workshop series was implemented to bring together diverse community experts (n= 30), including mothers with IDD/BH, to discuss the experiences of mothers and set priorities for treatment/services, systems, and research. Participants completed background and evaluation surveys and brainstormed, grouped, and ranked items of importance, which fell into two broad categories: (1) cross-cutting themes drawn from lived experience with recommendations applicable to all substantive domains (i.e., accessibility, diversity, adverse experiences and trauma, and trust) and (2) substantive themes with specific recommendations for treatment/services and systems (i.e., services and supports, peer support, provider practices and training, and systems navigation/transformation). Research recommendations were generated in all discussions and emerged in relation to all themes, underscoring the importance of including mother-driven questions and priorities in research agendas and strengthening researcher training and skills to engage mothers with IDD/BH and other community members actively, and in meaningful ways.