This research uses a conceptual model to examine the influence of a change in accreditation standards on a representative national sample of 203 engineering programs at 40 institutions. Based on data collected from 147 program chairs, 1,200 faculty, 4,300 graduates of 2004, and 5,500 graduates of 1994, the study investigates the differential impact of the change in accreditation standards on programs reviewed in different years during the period of transition. Despite significant variation across most of the measures and groups in 1994 (before the introduction of the new accreditation criteria), the 2004 evidence demonstrates a surprisingly uniform level of student experiences and outcomes. These findings suggest that engineering accreditation seems to be accomplishing its quality assurance goals. (Contains 9 figures, 5 tables, and 5 footnotes.) [This study was supported by a grant from the Accrediting Board of Engineering and Engineering Technology (ABET).]