In September 1998, the California State Legislature passed SB 2042, legislation that authorized the reform of teacher recruitment, certification, and licensing in the state. Its provisions are unique in that they represent the first time in California's history that almost all of the standards dealing with teacher preparation and induction were revised at the same time; every currently approved program that prepares teachers was requested to rewrite and submit program documents in a short time frame; the basic teaching credential was revised to carry the authorization to teach English Learners; and a requirement was created to mandate use of an assessment of teaching performance based on teaching performance expectations. The intent of SB 2042 was to use the California Standards for the Teaching Profession (CSTP), Teaching Performance Expectancies (TPEs), and a teacher performance assessment (TPA) and allied reform requirements to reform teacher education and prepare high quality teachers. The purpose of this research study was to evaluate the initial impact of SB 2042 on subject matter preparation and professional teacher preparation in California. The study has limited scope, as it took place over a six-month period and captured the impact on colleges, universities and school districts during the 2002-2003 academic year, the initial year of implementation. It also compared the experiences of early and late adopters of the reform. The findings provided feedback to the state on how the process worked, what the major successes and challenges were, and generated suggestions for the next phase of implementation. The main research questions were: (1) How did individuals and groups experience the process of implementing SB 2042 credential reform in CA? (2) What has been the impact of SB 2042 implementation on programs and curricula? (3) What has been the impact of credential reform on instructional and assessment practices (e.g., faculty development, candidate assessment, resources allocation)? (4) What has been the impact of credential reform on districts, other institutional partners, and other partners? and (5) How did early adopters differ from late adopters? (Contains 3 figures and 1 table.)