This article describes 10 lessons learned from two decades of new teacher induction. These include: (1) A new teacher induction program requires a systemwide commitment to teacher development; (2) Induction programs accelerate new teacher effectiveness; (3) Standards-based formative assessment tools document impact; (4) Induction programs build a pathway for leaders; (5) Good principals create a culture of learning; (6) Effective induction programs combine high-quality mentoring with communities of practice; (7) Teaching conditions matter to supporting and keeping new teachers; (8) Online communities provide timely, cost-effective mentoring; (9) Policy complements practice; and (10) Good induction programs are accountable, not just compliant. These lessons demonstrate that the best programs support novice teachers by tapping the expertise of veteran teachers, creating collegial groups that benefit all teachers and all students.