This academic book begins with a thorough explanation of career adaptability and its role in the Career Construction Theory model of career adaptation. The introductory chapter is followed by 18 chapters in which I review findings from 260 studies about career adaptability and integrate them into a body of scientific knowledge that can serve as a basis for further conceptualization and investigation. I organized the integration using a conceptual framework for programmatic research that progresses across five sequential stages, each with distinct research methods: survey, technique, critical, theoretical, and applied. The review of survey research discussed the existing literature related to career adaptability, followed by reflection on the findings that identified dimensions of the construct and variables to which it may relate. The review of technique research describes operational definitions with which to observe, quantify, and measure career adaptability. The review of critical research establishes a coherent nomological network of empirical relationships between career adaptability and related constructs. The review of theoretical research examines studies that tested hypotheses concerning relations among adaptivity, adaptability, adapting, and adaptation. And finally, the review of applied research concentrates on how educational, counseling, and coaching interventions can develop the career adaptability of students and employees. Appendices include four psychometric inventories: Career Adapt-Abilities Scale, Student Career Construction Inventory, Career Maturity Inventory, and Career Mastery Inventory.