All employers that wish to take part in the Wisconsin Retirement System must join and be covered by a Section 218 Agreement, which is an agreement between the state and the Social Security Administration (SSA) to provide Social Security coverage for state and local government employees.
The Comprehensive Annual Financial Report of the Wisconsin Department of Employee Trust Funds for the year ended December 31, 2016 provides comprehensive information about ETF, the Wisconsin Retirement System, and other benefit programs administered by ETF.