Although previous findings have shown that parents react intensely to the initial diagnosis of their child's disability, studies focused on long-term outcomes and adjustment are needed. We interviewed 21 mothers whose adolescent or young adult was diagnosed with Down syndrome or fragile X syndrome. Qualitative analysis of data focused on the diagnostic process and the child's development revealed emergent themes: importance of context, variations in emotional reactions to the diagnosis, use of specific coping strategies, and changes in family adaptation over time. Results indicate most families experienced elements of disruption and resilience in their reactions to the diagnosis, although different patterns emerged for each syndrome group. Maternal descriptions highlighted positive attributes that contributed to family well-being and behavioral challenges that were a source of family stress.