This brief describes the relationship between placement stability and youth engagement in the Youth Transitions Partnership (YTP), a program developed and implemented by the Alameda County Social Services Agency (SSA) for 14- to 20-year-olds in foster care who have multiple risk factors for experiencing homelessness. The authors used program data linked to child welfare administrative data to examine the proportion of YTP participants who experience placement instability while enrolled in the program. How this varies by age at enrollment is explored in particular, when YTP participants are most likely to experience placement instability, whether placement instability is associated with lower overall engagement, whether type of instability matters, and whether engagement is lower after youth experience placement instability.