These exceptions, based on the country of the worker`s nationality or nationality, are provisions of the Social Security Act. In most cases, aggregation agreements further expand the portability of benefits on the basis of residence. For the purposes of the FICA, “wages” are defined in Article 3121(a) as all remuneration for employment. Sec. 3121(b) for the purposes of the FCCA, generally defines employment as any service provided by a worker to an employer, regardless of the citizenship or residence of a United States in the United States or a service provided outside the United States by an American. . . .