"The Windfall Elimination Provision [WEP] and the Government Pension Offset [GPO] ... can reduce regular Social Security benefits ... if the worker is entitled to a pension based on earnings from employment that is not covered by Social Security.... Social Security Statements sent to workers do not consider WEP and GPO until the person applies for benefits.... [At] the time of application many individuals ... may learn they will not receive as much income as expected[.]"