<p>Housing instability affects millions of families and has been linked to increased child maltreatment risk, yet the mechanisms underlying this relationship remain poorly understood. Using data from the Future of Families and Child Wellbeing Study (<i>N</i> = 4,588), structural equation modeling was employed to test the mediating effect of instrumental social support in the relationship between housing instability (year 1) and different types of child maltreatment (year 5). Housing instability at year 1 was negatively associated with instrumental social support at year 3 (<i>β</i> = − 0.066, <i>p</i> &lt; .001). Social support showed differential associations with maltreatment types: positive associations with physical abuse (<i>β</i> = 0.050, <i>p</i> &lt; .01) and psychological aggression (β = 0.054, <i>p</i> &lt; .05), but a negative association with neglect (<i>β</i> = − 0.049, <i>p</i> &lt; .01). Significant indirect effects were found for all three maltreatment types, though effect sizes were small. Findings suggest that housing instability erodes instrumental social support networks over time, with complex implications for different types of maltreatment. Results highlight the need for interventions that address both housing instability and the quality of social support networks, recognizing that some sources of support may transmit harmful parenting norms while providing material assistance.</p>