This issue brief provides guidance for how states and territories can ensure that they meet Child Care and Development Fund (CCDF) requirements that co-payments are affordable and do not act as a barrier to families seeking child care subsidy. It includes a series of questions for lead agencies to consider when designing sliding fee scales, what states may exclude as countable income, an example of a sliding fee scale from Michigan, and a list of how 22 states and two territories have set dollar amounts. This information is important for school-age system planners who may work in partnership with CCDF on setting co-payments.