As a result of the passage of the Affordable Care Act, the behavioral healthcare field is experiencing an increased demand for services. This increase is based on the availability of healthcare coverage to an estimated 13.4 million previously uninsured individuals. To meet this demand for treatment, the workforce of behavioral health therapists must grow. The largest generation entering the workforce, the Millennial Generation - those born after 1980 - is believed to lack commitment to their employers, frequently vacating their positions for the next best offer. The purpose of this case study was to determine factors that both affect retention and contribute to employee turnover among Millennial behavioral health therapists, in the hope of identifying approaches for retaining them in not-for-profit organizations. This exploration used Rousseau's psychological contract theory as the theoretical lens. Secondary data from academic literature, public media, and published surveys were collected and analyzed using open coding to identify patterns and trends. Key variables influencing retention were parity in compensation, organizational culture, the opportunity to advance careers, and make a difference in the community. The implications for social change include informing policy makers and organizational leaders in behavioral healthcare about developing creative methods to increase retention. Recommendations include employer evaluation and improvement in their organizational culture and quality of relationships with their employees. The implementation of these recommendations could result in improved client outcomes, fiscal integrity, and organizational continuity.