In growing numbers, people with intellectual and developmental disabilities are outliving their parents, or at least their parents' ability to care for them. Consequently, adult siblings without intellectual and developmental disabilities are increasingly taking on primary caregiving responsibilities. However, adult siblings have received little study generally, and sibling caregivers have received even less. We used nationally representative data from the Survey of Income and Program Participation (SIPP) to describe the social characteristics and material hardship levels of sibling caregivers, in comparison to the general working age adult population. This study finds moderate material hardship to be pervasive among sibling caregivers, though extreme levels of hardship are possibly being abated somewhat through public benefit programs. Implications for greater service needs are discussed.