The ACT College Readiness Benchmarks are the ACT® College Readiness Assessment scores associated with a 50% chance of earning a B or higher grade in typical first-year credit-bearing college courses. The Benchmarks also correspond to an approximate 75% chance of earning a C or higher grade in these courses. There are four Benchmarks, corresponding to the four ACT subject area test scores linked to common first-year courses: ACT English/English Composition I, ACT Mathematics/College Algebra, ACT Reading/social science courses, and ACT Science/Biology. This report updates the Benchmarks, first established in 2005, with more current data. We found no change in the English and Mathematics Benchmarks; the Reading Benchmark increased from 21 to 22; and the Science Benchmark decreased from 24 to 23. The ACT College Readiness Benchmarks are applicable to 11th and 12th grade students who take the ACT. ACT Explore® (grade 8 and 9) and ACT Plan® (grade 10) Benchmarks are the scores associated with a 50% chance of meeting the ACT Benchmarks. In this study, we also updated the Explore and Plan Benchmarks. This report describes potential uses of the Benchmarks, including 1) targets for monitoring K-12 academic progress, 2) indicators of academic readiness within multiple-measure systems for college course placement and intervention, and 3) indicators to monitor educational progress at the local, district, state, and national levels. The following tables are appended: (1) Course Content Codes Used for ACT Postsecondary Research; (2) Demographics of Student Samples by College Course; (3) Aggregate Academic Achievement of Student Samples by College Course; (4) Student Samples for Explore and Plan Benchmarks; (5) Parameter Estimates from Hierarchical Logistic Regression Models for Course Success; and (6) Parameter Estimates from Logistic Regression Models for Explore and Plan Benchmarks.