The agreement with the Slovak Republic was effective on May 1, 2014.

If both the U.S. and Slovak social security systems cover a worker’s employment or self-employment, the agreement provides that beginning May 1, 2014, only one country’s system will cover the worker’s employment or self-employment. The agreement does not affect a worker's coverage prior to that date. If a worker had dually covered earnings before May 1, 2014, those earlier earnings were and would continue to be subject to social security contributions in both countries.