'...One class of people affected are those who receive a pension from a job in which they haven't paid Social Security FICA taxes, such as public-sector workers like police officers and firefighters. Many federal, state and local employees are enrolled in retirement systems that are not part of Social Security. Federal employees hired before 1984 who stayed under Civil Service Retirement System (CSRS) are affected. Federal workers who retired under the newer Federal Employee Retirement System (FERS) are not subject to WEP because they paid Social Security FICA taxes. Some foreign workers are also affected...'