Using data from the first National study on high school preparation for college calculus success, the Factors Influencing College Success in Mathematics (FICSMath) project, this article connects student high school instructional experiences to college calculus performance. The findings reported here reveal that students were better prepared for college calculus success by high school instructional experiences that emphasized mathematical definitions, vocabulary, reasoning, functions, and hands-on activities. These findings serve to inform high school mathematics teachers about promising instructional practices. They can also inform teacher education programs about how to better prepare secondary mathematics educators to discuss conceptual understanding on the widely used Educative Teacher Performance Assessment (edTPA).