All families in this study are housed. This study sets out to define and measure inadequate housing, hidden homelessness, and the risk of absolute homelessness in a low-income, housed population. This includes families on a continuum of housing vulnerability and homelessness, from inadequate and precarious housing, to hidden homelessness, to visible homelessness and shelter use, to re-housing after a period in a shelter. Families often move back and forth along this continuum.