This is the first in a series of papers the Center on Budget and Policy Priorities will publish related to the new Temporary Assistance for Needy Families (TANF) regulations. On April 12, 1999, the Department of Health and Human Services issued the final TANF regulations. They include many provisions, some of which reflect significant changes from the proposed regulations, that affirm and enhance the flexibility of states to determine how best to use TANF funds to assist low-income families. This paper describes selected requirements of the new regulations. Future papers will address the policy choices and opportunities available to states as they design and refine welfare policies that assist families move to work. In addition, a few areas of interest are omitted from this paper because further clarification is needed; these include the rules that apply to providing benefits and services, including assistance, to noncustodial parents.