401 (a) is a tax-adjourned retirement savings plan in the USA. Usually the plan is established by an employer and contributions to it are made by either the employer or both employee and employer, depending on policies.
Contribution values, be it dollar-based or percentage-based, and everything else required are decided by the supporting employer.
Employees working in the government sector, some specific educational institutions and NPOs are eligible for 401(a) plans. If or when an employee changes jobs their funds can be rolled over to a different retirement plan too, like 401(k) or IRA.
Contributions from employers’ side are obligatory, whereas employees don’t necessarily need to make the contributions. Furthermore early withdrawals from 401(a) plan are allowed, but penalties can be charged according to the policies.