The RETAIN Act creates a federal tax credit to help address teacher and early childhood educator shortages by rewarding educators who stay in the profession. The credit applies to eligible teachers, early childhood educators, school leaders, paraprofessionals, and school-based mental health workers at high-poverty schools and qualifying early childhood education programs. The credit amount ranges from $5,800 in the first two years of employment up to a maximum of $11,600 in the tenth year, then gradually decreases, with no credit available after twenty years of service. The credit takes effect for tax years beginning after December 31, 2023, and amounts will be adjusted annually for inflation starting in 2025. The legislation also requires the Labor Department to develop a public data series tracking teacher and early childhood educator salaries, updated annually, to monitor workforce trends.