When an adult child asks to move back home, saying yes may feel like the easiest part of the conversation. The harder questions often involve money: Will they pay rent, buy groceries, cover utilities, or save toward moving out? Those details matter because an adult child moving back home can change both the household budget and the parent-child relationship. Pew Research Center reported in 2025 that 18% of Americans ages 25 to 34 were living in a parent’s home in 2023. Before anyone carries a box through the front door, families should agree on financial expectations that help the arrangement work for everyone.