Traditional standardized testing focuses on rote memorization and low-level skills, failing to adequately evaluate if students have mastered higher-order competencies needed for post-secondary success. Competency-based education aims to develop mastery of key abilities through personalized, flexible learning. However, assessment practices must also shift to authentic tasks that mirror real-world applications. This article examines how authentic assessment supports competency-based learning goals. Authentic assessments embed evaluation within open-ended, complex projects, performances and problems set in contexts similar to work, community or post-secondary education. Through authentic tasks, students demonstrate mastery of collaboration, problem-solving, communication and other transferable skills. Feedback is ongoing to support continuous improvement. Research indicates authentic assessment is a valid measure of competency attainment. Data from three competency-based high schools that implemented portfolio-based, performance-based and product-based assessments show such tools reliably indicate students' mastery of collaboration, digital literacy and other targeted competencies. Authentic assessment also increases student engagement and motivation by connecting learning to meaningful work. This evidence suggests authentic assessment should be a core practice for any competency-based learning model seeking to fully evaluate student competency development.