Students must choose when to take the ACT for the first time and if and when to retest. States and districts that administer the ACT test to all students must also choose when to administer the test. A key consideration in making these decisions is the impact on scores. Because the ACT is a curriculum-based test of academic achievement, students generally score higher later in their high school career. This brief provides answers to four questions related to the question of when to take the ACT: (1) What is equating and how does it affect interpretation of ACT test scores; (2) Do students who test later in their high school career perform better than students who test earlier in their career; (3) In grade 11, does it matter when during the school year students take the ACT; and (4) Do students who retest on the ACT increase their scores?