The agreement with Switzerland became effective on August 1, 2014. This supplementary agreement replaces the November 1, 1980 agreement and a later amendment effective October 1, 1989.

If a worker's employment or self-employment is subject to both U.S. and Swiss social security coverage and taxation laws, the agreement provides that beginning August 1, 2014, only one country's social security coverage and taxation laws cover the worker's employment or self-employment. If a worker's employment or self-employment was subject to both U.S. and Swiss social security coverage and taxation laws prior to that date, effective November 1, 1980, the original agreement provides that the worker's employment or self-employment is subject to only one country's laws. If a worker's employment or self-employment was subject to both countries' social security coverage and taxation laws before November 1, 1980, that earlier employment or self-employment remains subject to those laws in both countries.