Previous research has established the importance of family instability for child outcomes, theorizing that changes in family composition disrupts routines and inhibits effective parenting. Estimates of childhood exposure to family instability has typically focused on transitions of mothers into and out of marital and cohabiting relationships. Yet, there are many other potential sources of household instability which might also disrupt routines. This research produces estimates of household instability in the United States, based on data from the 2008 and 2014 Surveys of Income and Program Participation (SIPP). Overall we find that marital-cohabitation transitions are only a small portion of family transitions children are exposed to. We also find substantial variation across race-ethnicity and maternal education.