This report uses the phrase, "College Readiness" to refer in a general sense to the level of preparation a student needs to be ready to enroll and succeed--without remediation--in a credit-bearing course at a two-year or four-year institution, trade school, or technical school. Increasingly, however, college readiness also means "workplace" readiness. While not every student plans to attend college after high school, many of the jobs now being created in a highly technology-based economy require abilities equivalent to those expected of the first-year college student. ACT research confirms the results and benefits of a rigorous core preparation curriculum for all students, whether they plan to go on to college or to work after high school (ACT, 2004). However, their research has also led them to rethink whether the core curriculum--as traditionally defined in terms of numbers of courses--adequately prepares students for success after high school. This document is directed at a diverse audience: educational leaders and policymakers at all levels involved with secondary and postsecondary education and business and community leaders concerned about the preparation of the next generation of workers. This report aims to: alert these individuals to vital new information about the students they serve; and to offer recommendations that will help them make the crucial decisions that affect the schools and students in their districts, regions, states, and the nation at large. An appendix provides detailed information on the data sources and methodologies used in this report. (Contains 37 figures.)