This study analyzes major comparative law cases to examine the legal justifications and limitations surrounding discussions on extending the mandatory retirement age. In the United States, amendments to the Age Discrimination in Employment Act (ADEA) have, in principle, prohibited mandatory retirement systems. Japan, in parallel with the gradual increase in the pensionable age under the Employees’ Pension Insurance Act, has implemented phased institutional reforms—setting the mandatory retirement age at 60, introducing continued employment up to 65, and imposing a duty on employers to make efforts to secure employment opportunities until 70. Within the European Union, mandatory retirement systems are permitted only when justified by legitimate social policy objectives under the principle prohibiting age discrimination, and this approach has been concretized differently in Germany, France, and the United Kingdom.
Through this comparative legal analysis, the study identifies several key considerations for future discussions on the mandatory retirement age in Korea. First, the mandatory retirement system is not a self-evident institution; it requires social policy justification consistent with, yet in tension with, the principle of age discrimination prohibition. Second, while extending the mandatory retirement age is an inevitable response to the income gap caused by the increase in the National Pension payment age, it must be accompanied by a comprehensive reorganization of the labor law framework, including reforms to corporate personnel and wage systems, a reassessment of dismissal regulations, and stricter controls on fixed-term employment. Third, ensuring the effectiveness of retirement age extension requires not merely legislative reform but also a comprehensive support system to maintain older workers’ skills, safeguard their health, and facilitate job transitions.