The Windfall Elimination Provision (WEP) is a provision in United States law
that changes the way your U.S. Social Security benefits are calculated. WEP can
reduce your U.S. retirement or disability benefits if you receive a pension
based on work and you did not pay U.S. Social Security taxes on those earnings.
Windfall Elimination Provision Fact Sheet
This site contains a WEP Screening Tool for foreign pensions. By answering a few questions in this tool, you can learn if WEP will reduce your U.S. Social Security benefit.