<p>Past research on teacher shortages due to turnover has not adequately distinguished between teachers leaving the profession (attrition) and moving between schools (migration), hindering the identification of tailored retention strategies for schools and/or the profession. This study, part of a comprehensive project including a systematic review, meta-analysis, and empirical investigation, surveyed 930 current and former K-12 teachers in Victoria, Australia. It explored their reasons for quitting, migrating, or remaining in the profession. Thematic analysis revealed that career factors and school characteristics primarily drive migration, whereas personal life stages and role compatibility influence attrition. Factors supporting retention include personal choice, job compatibility, and positive relationships with students and colleagues. Migration often stems from a quest for professional advancement and dissatisfaction with school culture. Conversely, attrition is predominantly driven by job dissatisfaction and burnout. The findings suggest that while migration can yield positive outcomes for departing teachers, some teachers may feel compelled to stay due to factors like poor employability, fear of change, or personal obligations. Importantly, the study captured voluntary and involuntary career decisions, with the latter often overlooked previously. This research underscores the need for tailored strategies that acknowledge and address both voluntary and involuntary aspects of teacher turnover.</p>