Preserve Rights Of States and Political subdivisions to Encourage Retirement Savings Act or the PROSPERS Act This bill amends the Employee Retirement Income Security Act of 1974 (ERISA) to specify that states and certain political subdivisions may establish and administer voluntary payroll deduction retirement savings programs for private sector employees that are not considered employee pension benefit plans or pension plans covered by ERISA if the plans meet certain requirements. The bill requires the plans to be established, implemented, and administered by states or political subdivisions. The plans must also be voluntary for employees and meet other specified requirements, including restrictions on the involvement of employers and obligations to enforce the rights of employees.