In this report, the General Accounting Office (GAO) examined how different states are implementing the work requirements and time limits called for by the Temporary Assistance for Needy Families (TANF) program. Data were collected from site visits in 4 states, telephone interviews with TANF officials in 8 additional states, and a survey administered to TANF officials in all 50 states and the District of Columbia. During fall 2001, states were providing cash assistance funded by federal TANF or state maintenance-of-effort (MOE) dollars to 2.1 million families. For one-third of the cash assistance caseload, only the children in families received assistance. Almost all states met or exceeded their adjusted required work participation rate in fiscal 2000. Among the states, fiscal 2000 federal participation rates ranged from about 6% to more than 70%. States excluded about 11% of the 1.4 million families with adult receiving cash assistance. Time limit exclusions were generally targeted toward families considered hard to employ, families that were working but not earning enough to leave TANF, and families that were cooperating with program requirements but had not yet found employment. Nine appendixes contain data on states' funding choices, separate state program caseloads and characteristics, state-defined work rates, and work requirements. (Contains 12 tables.) (MN)