Section 404.1901 - Introduction(a) Under section 233 of the Social Security Act, the President may enter into an agreement establishing a totalization arrangement between the social security system of the United States and the social security system of a foreign country. An agreement permits entitlement to and the amount of old-age, survivors, disability, or derivative benefits to be based on a combination of a person's periods of coverage under the social security system of the United States and the social security system of the foreign country. An agreement also provides for the precluding of dual coverage and dual social security taxation for work covered under both systems. An agreement may provide that the provisions of the social security system of each country will apply equally to the nationals of both countries (regardless of where they reside). For this purpose, refugees, stateless persons, and other nonnationals who derive benefit rights from nationals, refugees, or stateless persons may be treated as nationals if they reside within one of the countries.(b) The regulations in this subpart provide definitions and principles for the negotiation and administration of totalization agreements. Where necessary to accomplish the purposes of totalization, we will apply these definitions and principles, as appropriate and within the limits of the law, to accommodate the widely diverse characteristics of foreign social security systems.