The agreement with Italy is a departure from other US agreements because it does not regulate the people cashed in. As in other agreements, the basic criterion of coverage is the territorial rule. However, the coverage of foreign workers is mainly based on the nationality of the worker. If an employed or self-employed U.S. citizen in Italy would be covered by U.S. Social Security without the agreement, he will remain covered by the U.S. program and exempt from Italian coverage and contributions. The goal of all U.S. totalization agreements is to eliminate dual social security and taxation, while maintaining coverage for as many workers as possible under the country where they are likely to have the most ties, both at work and after retirement.
Any agreement aims to achieve this objective through a series of objective rules. One of the general beliefs about the U.S. agreements is that they allow dual-coverage workers or their employers to choose the system to which they will contribute. That is not the case. The agreements also do not change the basic rules for covering the social security legislation of the participating countries, such as those that define covered income or work. They simply free workers from coverage under the system of either country if, if not, their work falls into both regimes. The detached house rule may apply if the U.S. employer transfers a worker to work at a foreign branch or in one of its foreign subsidiaries.
However, in order for U.S. coverage to continue when a transferred employee works for a foreign subsidiary, the U.S. employer must have entered into a Section 3121 (l) agreement with the U.S. Treasury Department with respect to the foreign subsidiary. International social security agreements are beneficial for both those who work today and those whose careers are over. For current workers, the agreements eliminate the double contributions they might otherwise make to social security plans in the United States and another country. For people who have worked in the United States and abroad and are now retired, disabled or deceased, agreements often result in the payment of benefits to which the worker or family members would not otherwise be entitled. The agreements also have a positive effect on the profitability and competitive position of companies operating abroad by reducing their business costs abroad.
Companies with staff stationed abroad are encouraged to use these agreements to reduce their tax burden. The provisions to eliminate dual coverage for workers are similar in all U.S. agreements. Each of them establishes a basic rule regarding the location of the employment of a workforce. Under this basic „territorial rule,” a worker who would otherwise be covered by both the United States and a foreign regime is subject exclusively to the coverage laws of the country in which he or she works. Under certain conditions, a worker may be exempt from coverage in a contracting country, even if he or she has not been transferred directly from the United States. For example, if a U.S. company sends an employee to its New York office to work for 4 years in its Hong Kong office, and then re-opens the employee for an additional 4 years in its London office, the employee may be a member of Social Security under the U.S.U.K. agreement. The rule for the self-employed applies in cases such as this, provided the worker has been seconded from the United States and is under U.S.
Social Security for the entire period prior to the transfer to the contracting country.