The ACT College Readiness Benchmarks are the ACT scores associated with a 50% chance of earning a B or higher grade in selected first-year credit-bearing courses at a typical postsecondary institution. The Benchmarks were established by linking ACT test scores with grades in first-year college courses from the same subject area. Benchmarks were first established for ACT English, Mathematics, Reading, and Science scores (Allen & Sconing, 2005; Allen, 2013) and have also been established for ACT STEM (Mattern, Radunzel, & Westrick, 2015; Radunzel, Mattern, Crouse, & Westrick, 2016) and ACT ELA scores (Radunzel, Westrick, Bassiri, & Li, 2017). Table 1 provides the ACT College Readiness Benchmarks and the respective college courses used to establish the Benchmarks. Students scoring at each Benchmark have a 50% chance of earning a B or higher grade in the respective course or courses at a typical postsecondary institution, and approximately a 75% chance of earning a C or higher grade. The purpose of this brief is to present the full range of course success probabilities, by ACT test score, for each of the college courses or course combinations listed in Table 1.