On its twentieth anniversary, Taiwan’s National Health Insurance (NHI) stands out as a high-performing single-payer national health insurance system that provides universal health coverage to Taiwan’s 23.4 million residents based on egalitarian ethical principles. The system has encountered myriad challenges over the years, including serious financial deficits. Taiwan’s government managed those crises through successive policy adjustments and reforms. Taiwan’s NHI continues to enjoy high public satisfaction and delivers affordable modern health care to all Taiwanese without the waiting times in single-payer systems such as those in England and Canada. It faces challenges, including balancing the system’s budget, improving the quality of health care, and achieving greater cost-effectiveness. However, Taiwan’s experience with the NHI shows that a single-payer approach can work and control health care costs effectively. There are lessons for the United States in how to expand coverage rapidly, manage incremental adjustments to the health system, and achieve freedom of choice.