Past research has predominantly used the Career Adapt-Abilities Scale total score to indicate career adaptability and found promising evidence for the importance of career adaptability. However, there remains a critical gap between the research popularity and the incremental validity of the CAAS total score, which concerns its additive predictions for career criteria beyond general self-efficacy. To solidify the empirical foundation of career adaptability, we used a sample of employees (n = 284) and a sample of students (n = 279) to examine the incremental predictions of the CAAS total score for career adaptation responses and results over and beyond general self-efficacy. The results revealed that while the CAAS total score additively predicted career decision self-efficacy over and beyond general self-efficacy in students, the CAAS total score demonstrated no or little additive predictions for occupational self-efficacy, career decision self-efficacy, career decision ambiguity aversion, career satisfaction, major satisfaction, and career indecision over and beyond general self-efficacy. We discussed the implications of this study for adaptability research, assessment, and practice together with the limitations and suggestions for future research.