The agreement with Brazil became effective on October 1, 2018.

If both the U.S. and Brazilian social security systems cover a worker’s employment or self-employment, the agreement provides that beginning October 1, 2018, only one country’s system will cover the worker’s employment or self-employment. The agreement does not affect any worker's coverage prior to that date. If a worker had dually covered earnings before October 1, 2018, those earlier earnings would continue to be subject to social security taxes in both countries.