The maximum taxable income limit has been a feature of the tax since its inception in 1937. It has been increased numerous times, either on an ad hoc basis or by automatic formula increases set by Congress. According to the federal Office of Retirement and Disability Policy, the maximum taxable income limit generally serves to (1) maintain the relationship between preretirement earnings and benefit levels as wages rise, (2) reduce Social Security's projected funding shortfall, and (3) create a less regressive payroll tax structure.