SSA administers the Old Age, Survivors, and Disability Insurance programs under Title II of the Social Security Act. About 96 percent of the nation’s work force is in social security-covered employment and pays tax on their annual earnings. When workers pay social security taxes, they earn coverage credits, and 40 credits—equal to at least 10 years of work— entitle them to social security benefits when they reach retirement age. In 1977, the Congress authorized the President to enter into totalization agreements with other countries. These bilateral agreements are intended to accomplish three purposes. First, they eliminate dual social security coverage and taxes that multinational employers and employees encounter when they operate and their workers temporarily reside and work for the corporation, usually no more than 5 years, in a foreign country with its own social security program. Under the agreements, U.S. employers and their workers sent temporarily abroad would benefit by paying only U.S. social security taxes, and foreign businesses and their workers would benefit by paying only social security taxes to their home country. Second, the agreements provide benefit protection to workers who have divided their careers between the United States and a foreign country, but lack enough coverage under either social security system to qualify for benefits, despite paying taxes into both systems. Totalization agreements allow such workers to combine (totalize) work credits earned in both countries to meet minimum benefit qualification requirements. Third, most totalization agreements improve the portability of social security benefits by removing rules that suspend benefits to noncitizens who live outside the benefit-paying country. By law, proposed agreements are sent to the Congress together with a report on the effects on the agreement. Under the statute, the agreement becomes effective on any date provided in the agreement after one House of the Congress has been in session 60 days, unless either House of the Congress adopts a resolution of disapproval. Table 1 shows agreements in effect and the years they became effective. To qualify for totalized U.S. social security benefits, a worker must have at least 6 but no more than 39 U.S. coverage credits. Benefit amounts are based on the portion of time a foreign citizen worked in the United States and, thus, are almost always lower than full social security benefits. The average monthly, totalized social security benefit at the end of 2001 was $162, compared with the average nontotalized monthly social security benefit of $825. In 2001, SSA paid about $173 million under totalization agreements to about 89,000 persons, including their dependents. Under U.S. law, immigrants may not work in the United States unless specifically authorized. Nevertheless, immigrants often do work without authorization and pay social security taxes. Under the Social Security Act, all earnings from covered employment in the United States count towards earning social security benefits, regardless of the lawful presence of the worker, his or her citizenship status, or country of residence. Immigrants become entitled to benefits from unauthorized work if they can prove that the earnings and related contributions belong to them. However, they cannot collect such benefits unless they are either legally present in the United States or living in a country where SSA is authorized to pay them their benefits. Mexico is such a country. A lack of transparency in SSA’s processes, and the limited nature of its review of Mexico’s program, cause us to question the extent to which SSA will be positioned to respond to potential program risks should a totalization agreement with Mexico take place. SSA officials told us that the process used to develop the proposed totalization agreement with Mexico was the same as for prior agreements with other countries. The process—which is not specified by law or outlined in written policies and procedures—is informal, and the steps SSA takes when entering into agreements are neither transparent nor well-documented. Current law does not prescribe how SSA should select potential agreement countries. According to SSA, interest in a Mexican agreement dates back more than 20 years. SSA officials noted that increased business interaction between the two countries due to the North American Free Trade Agreement (NAFTA) was a factor in the renewed negotiations. In addition, because there is a totalization agreement with Canada, our other NAFTA partner, SSA believed that equity concerns required consideration of an agreement with Mexico. In February 2002, SSA sought clearance from the Department of State to begin such negotiations. The law also does not specify which elements of other countries’ social security systems must be evaluated during totalization agreement negotiations. SSA officials met with Mexican officials to exchange narrative information on their respective programs. Senior SSA officials also visited Mexico for 2 days in August 2002. During their visit, these officials told us that they toured social security facilities, observed how Mexico’s automated social security systems functioned, and identified the type of data maintained on Mexican workers. SSA took no technical staff on this visit to assess system controls or data integrity processes. In effect, SSA only briefly observed the operations of the Mexican social security program. Moreover, SSA did not document its efforts or perform any additional analyses then, or at a later time, to assess the integrity of Mexico’s social security data and the controls over that data. In particular, SSA officials provided no evidence that they examined key elements of Mexico’ s program, such as its controls over the posting of earnings, and its processes for obtaining key birth and death information for Mexican citizens. Nor did SSA evaluate how access to Mexican data and records is controlled and monitored to prevent unauthorized use or whether internal and external audit functions exist to evaluate operations. Because all totalization agreements represent a financial commitment with implications for social security tax revenues and benefit outlays, a reasonable level of due diligence and analysis is necessary to help federal managers identify issues that could affect benefit payment accuracy or expose the nation’s system to undue risk. Our Internal Control Management and Evaluation Tool provides a risk assessment framework to help federal managers mitigate fraud, waste, abuse, and mismanagement in public programs, such as social security. A key component of this framework is the identification of internal and external risks that could impede the achievement of objectives at both the entity and program levels. Identified risks should then be analyzed for their potential effect and an approach devised to mitigate them. SSA did not conduct these types of analyses in previous agreements or in the case of the proposed Mexican agreement, despite documented concerns among Mexican government officials and others regarding the integrity of Mexico’s records, such as those for birth, death, and marriage, as well as its controls over assigning unique identification numbers to workers for benefit purposes. Such information will likely play a role in SSA’s ability to accurately determine Mexican workers’ initial and continuing eligibility for benefits under a totalization agreement. A totalization agreement with Mexico will increase the number of Mexican citizens who will be paid U.S. social security benefits in two ways. First, the agreement will make it easier for Mexican workers to qualify for benefits. Second, it will remove some nonpayment restrictions that affect benefit payments to non-U.S. citizens’ family members residing in another country, thus providing U.S. social security benefits to more survivors and dependents of entitled Mexican workers. Under current law, a worker must earn sufficient coverage credits to qualify for benefits under the U.S. Social Security program. For example, a worker who was born in 1929 or later generally needs 40 coverage credits to be insured for retirement benefits. Credits are based on a worker’s annual earnings in social security-covered employment. At most, 4 credits can be earned per year so that it takes at least 10 years of covered earnings in the United States for a worker to accumulate the necessary 40 credits and become insured for retirement benefits. Currently, social security credits are earned by anyone who has worked in covered employment in the United States. This is true even if the person was unauthorized to work when he/she earned coverage credits. For example, noncitizens, including Mexicans, who are at least 62 years old and lawfully present in the United States, will receive retirement benefits today as long as they meet the coverage credit threshold. Even Mexican citizens who are not lawfully present in this country can receive social security benefits earned through unauthorized employment if they later return to live in Mexico. Similarly, under current law, noncitizen dependents and survivors can also receive social security benefits under some circumstances. Totalization agreements generally expand benefits to both authorized and unauthorized workers and create new groups of beneficiaries. This would be the case for a totalization agreement with Mexico if it follows the same pattern as all prior totalization agreements. Mexican citizens with fewer than 40 coverage credits will be permitted to combine their annual earnings under their home country’s social security program with their annual earnings under the U.S. Social Security program to meet the 40- credit requirement. In addition, more family members of covered workers will qualify for dependent and survivor benefits. Totalization agreements generally override Social Security Act provisions that prohibit benefit payments to noncitizens’ dependents and survivors who reside outside the United States for more than 6 months, unless they can prove that they lived in the United States for 5 years in a close family relationship with the covered worker. If a totalization agreement with Mexico is structured like others already in force, the 5-year rule for dependents and survivors will be waived. However, it is important to understand that not all unauthorized Mexican citizens who have worked in the United States will receive totalization benefits. Some will have earned at least 40 coverage credits and can receive social security benefits without a totalization agreement. Still others may have worked under false identities and may not be able to prove that they have the necessary coverage credits to be entitled to benefits. Others still may not accumulate sufficient credits under the Mexican social security system to totalize with their U.S. social security coverage. The cost of a totalization agreement with Mexico is highly uncertain.