The purpose of this sequential mixed methods study was to examine the relationship among student achievement factors, gifted and talented status and post-secondary readiness. The study included a review of archived data obtained from a large district in the southeastern region of Texas consisting of a purposeful sample of AP students' who took an Advanced Placement exam in AP English and/or AP Calculus AB in the spring of 2019. A purposeful sample of 10 AP teachers were also interviewed in an attempt to provide a more in-depth understanding of the impact student achievement factors, gifted and talented status had on post-secondary readiness. Results indicated that there was a positive correlation between: (a) overall high school GPA and post-secondary readiness, (b) PSAT scores in reading and mathematics and post-secondary readiness, (c) STAAR EOC scores in English II and Algebra I and post-secondary readiness, and (d) gifted and talented status and post-secondary readiness in English. On the other hand, the results did not indicate a positive correlation between gifted and talented status and post-secondary readiness in mathematics. Although, the majority of AP teachers agreed student achievement factors could be good indicators of students' ability to grasp the content there was no agreement on which factors provided the best indication. The majority of AP teachers agreed GPA showed a students' grit and self-regulation but could be misconducted due to weighted GPA. On the other hand, the majority of AP teachers did not support the use of standardized test scores as a valid indicator for post-secondary readiness. AP teachers also expressed mixed feelings about gifted and talented status and post-secondary readiness which was mainly due to GT students' lack of motivation and lack of reevaluation process. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]