This report concludes the main portion of MDRC's Project on Devolution and Urban Change, an eight-year effort to chart the course of welfare reform in four big urban counties: Los Angeles, Cuyahoga (Cleveland), Miami-Dade, and Philadelphia. The goal of the study was to find out whether federal welfare reform would lead to meaningful changes in urban welfare bureaucracies and to learn how time limits and other policies would affect the poorest families and neighborhoods. Given the broad sweep of the overhaul, the Urban Change study used a variety of qualitative and quantitative methods to examine how governments, neighborhoods, and families experienced welfare reform over a several-year period. This report describes what we found in Los Angeles County, but it also offers lessons from across the four sites that are important for assessing the success of welfare reform so far and for continued discussions about the reauthorization of the federal program. (Contains 43 tables, 43 figures, and 1 box.) Appended are: (1) supplemental tables; and (2) methodological notes. [Report written with Sarah Rich. Dissemination of MDRC publications is also supported by the Starr Foundation.]