The amount of household debt tripled globally over the last decades and a sizable share of individuals and families are overindebted due to mortgages, credit cards, or consumer debt. Yet research on the distribution of debt across families, and potential ripple effects of the psychological burden related to debt on well-being and family relations, remains sparse. Our study aims to fill these gaps by examining the socio-demographic profiles of families that have accumulated household debt and the unique role that the psychological burden related to debt plays on associations between mothers’ well-being, parental dynamics, and child adjustment based on the Family Stress Model (FSM). We used representative survey data collected in 2019 from Germany (N = 3271), which is one of the richest economies worldwide, yet about 10% of adults reported to be overindebted. Logistic regression results showed that single mothers were less likely to have debt compared to mothers in two-parent families. However, both single mothers and mothers in stepfamilies with high levels of perceived economic strain were particularly likely to report having debt. Structural equation modeling yielded that the links between the psychological burden of debt, maternal well-being, parental dynamics, and child adjustment were largely in line with the FSM, except for single mothers. We conclude that persisting financial disparities by family structure may be partially fostered by unique characteristics of the German welfare state, such as promoting more a traditional two-parent norm, and discuss our findings in light of practical implications.