Drawing on family development theory, this study provides insight into how family stages with and without siblings are related to media habits and effects. Two national samples (N = 527 and N = 1,257) present a cross-sectional snapshot of media uses in families across three stages of family life: families with preschoolers (2-6 years), with elementary school-age children (7-12 years), and with adolescents (13-17 years). We observed differences between family stages in five domains of media use: alternative activities to screen media, media use, parental monitoring, consistency in applying media rules, and resistance to media effects. Generally, more positive media habits were associated with families in earlier stages, families with siblings, and families with larger age gaps in sibling spacing. But greater vulnerability to media effects was associated with those families with multiple children and gaps in sibling spacing that spanned more than one stage.