AbstractBackgroundLittle is known about the heterogeneous nature of financial hardship in younger patients with metastatic disease and the extent to which insurance protects against it. We examine the association between insurance status and multidimensional indicators of financial hardship in a national sample of women with metastatic breast cancer.MethodsWe conducted a national, retrospective online survey in partnership with the Metastatic Breast Cancer Network. Eligible participants were ≥18 years, diagnosed with metastatic breast cancer, and able to respond in English. We estimated multivariate generalized linear models predicting two distinct dimensions of financial hardship—financial insecurity (the ability to afford care and living costs) and financial distress (the extent of emotional/psychological distress experienced due to costs)—as a function of insurance status.ResultsParticipants responded from 41 states (N= 1054; median age: 44 years). Overall, 30% were uninsured.Financial insecuritywas more frequently reported by uninsured respondents. In adjusted analyses, uninsured participants were more likely than insured participants to report contact by debt collectors (adjusted risk ratio [aRR]: 2.38 [2.06, 2.76]) and being unable to meet monthly expenses (aRR: 2.11 [1.68, 2.66]).Financial distresswas reported more frequently by insured participants. For example, insured participants were more likely to worry about future financial problems due to cancer and distress about lack of cost transparency. After adjustment, uninsured participants remained about half as likely as insured participants to report financial distress.ConclusionsYoung adult women with metastatic cancer reported a high burden of financial toxicity. Importantly, insurance does not protect against financial distress; however, the uninsured are the most materially vulnerable.