As a neglected dimension of the quality of care, assessments of caregiver reliability by older adults receiving help contributes to the better understanding of unmet needs for assistance in everyday life. This study examines how the numbers and composition of helpers - both potential and actual - relate to older Americans' reports of the reliability of assistance. According to the 2008 US National Elder Mistreatment Study (<i>n</i> = 2,176), the potential network, proxied by marital status and household size, was not a significant predictor of unreliable care, nor was the actual number of caregivers. We distinguish four types of helping sources: kin-only; exclusively informal non-kin (eg friends, neighbours); exclusively formal (paid); and mixed type. There was a higher risk of unreliable care among respondents relying exclusively on informal non-kin assistance compared with exclusively kin help. Kin-only provided more reliable care than informal non-kin but were no more reliable than formal or mixed types.