Employers are not legally required to offer a retirement plan to their employees. However, there are certain circumstances where employers may be required to provide retirement benefits. For example, if an employer chooses to offer a retirement plan, they must comply with the Employee Retirement Income Security Act (ERISA) if the plan meets certain criteria. Additionally, some states have implemented laws that require employers to offer retirement plans or participate in state-sponsored retirement programs. It's important to note that even if an employer is not legally obligated to offer a retirement plan, they may still choose to do so as a way to attract and retain employees. Employers should consult with legal and financial professionals to understand their specific obligations and options regarding retirement plans.