Effectively managing entitled employees continues to challenge managers, as it has for decades. Over three chapters, this dissertation creates a new avenue for managing entitlement at work by reconceptualizing the construct, operationalizing and validating a new measure, and using the new measure to experimentally test management tactics. The first chapter lays out a new, three-faceted Rationalized Entitlement Theory to better understand the structure of psychological entitlement. Considering entitlement as a mindset comprised of rationalized expectations, self-serving attributions, and perceptions of the self as a victim provides a more nuanced understanding of the underlying psychological mechanisms and their relationships to key workplace outcomes. The second chapter operationalizes this construct and validates the measure over multiple samples. The measure displays good psychometric reliability, as well as adequate convergent, discriminant, and incremental predictive validities. The third chapter uses the newly validated Rationalized Entitlement Measure to experimentally explore potential tactics for managing entitlement in the workplace. Entitlement is found to be a strong predictor of many workplace outcomes, with nuanced, often conflicting relationships between the subdimensions of entitlement and work outcomes. The results across these three chapters indicates entitlement is a nuanced, multidimensional construct and current entitlement research may benefit from paying more attention to the distinctive facets of entitlement.