Americans change residences frequently. Residential mobility can reflect positive changes in a family's circumstances or be a symptom of instability and insecurity. Mobility may also change neighborhoods as a whole. To shed light on these challenges, this report uses a unique survey conducted for the Making Connections initiative. The first component measures how mobility contributed to changes in neighborhoods' composition and characteristics. The second component identifies groups of households that reflect different reasons for moving or staying in place. The final component introduces five stylized models of neighborhood performance: each has implications for low-income families' well-being and for community-change efforts.