The Social Security program provides monthly cash benefits to retired or disabled workers and their dependents, and to the survivors of deceased workers. To qualify for benefits, workers (whether citizens or noncitizens) must work in Social Security-covered jobs for a specified period of time, among other requirements. Generally, workers need 40 earnings credits (also referred to as "quarters of coverage") to become "insured" for benefits (fewer credits are needed for disability and survivor benefits, depending on the worker's age). In 2017, a worker earns one credit for each $1,300 of covered earnings, up to a maximum of four credits for the year (i.e., with annual earnings of $5,200 or more). The Social Security program is financed primarily by mandatory payroll taxes levied on wages and self-employment income. Most jobs in the United States are covered under Social Security (about 94% of the work force is required to pay Social Security payroll taxes). In 2017, Social Security-covered workers and their employers each pay 6.2% of earnings up to $127,200 (this amount is increased annually according to average wage growth if a Social Security cost-of-living adjustment is payable). The self-employed pay 12.4% on net self-employment income up to $127,200 and may deduct one-half of payroll taxes from federal income taxes. The following workers are exempt from Social Security payroll taxes: State and local government workers who participate in alternative retirement systems. Election workers who earn less than $1,800 in 2017. Ministers who elect not to be covered, and members of certain religious sects. Most federal workers hired before 1984. College students who work at their academic institutions. Household workers who earn less than $2,000 in 2017, or those under age 18 for whom household work is not their principal occupation. Self-employed workers who have annual net earnings below $400. Noncitizens who work under the F, J, M, Q, and H-2A visa categories. In 2014, an estimated 14 million noncitizens were in the U.S. labor force comprising approximately 8.9% of the labor force. Foreign nationals who work in Social Security-covered employment must pay Social Security payroll taxes, including those who are in the United States working temporarily and those who may be working in the United States without authorization. There are some exceptions. In general, the work of aliens who are citizens of a country with which the United States has a "totalization agreement" (see below) is not covered by Social Security if they work in the United States for less than five years. In addition, by statute, the work of aliens under certain visa categories (such as H-2A agricultural workers, F and M students) is not covered by Social Security. An alien may be authorized to be in the United States, but not authorized to work. Therefore, a foreign national who does not have work authorization is not necessarily illegally present (i.e., an unauthorized alien). The Social Security Administration (SSA) maintains an Earnings Suspense File that tracks wages that cannot be posted to individual work records because the names and Social Security numbers (SSNs) on W-2 forms submitted by employers to SSA do not match SSA records. As of October 2016, through tax year 2014, the Earnings Suspense File included about 346 million wage items representing about $1.3 trillion in wages. The mismatched information may be due to typographical or other clerical errors (such as a misspelled name or an individual's failure to report a new married name to SSA), as well as the use of invalid or stolen SSNs by aliens who are working in the United States without authorization. In 2013, the SSA Office of the Chief Actuary (OCACT) estimated that about 3.1 million unauthorized aliens were working and paying Social Security taxes in 2010. Of those 3.1 million unauthorized foreign national workers, SSA estimated that 0.6 million had temporary work authorized at some point in the past and overstayed their terms of admittance (e.g., visas); 0.7 million obtained fraudulent birth certificates at some point and used these birth certificates to obtain an SSN; and 1.8 million used an SSN that did not match their name (i.e., fraudulently used another person's SSN). OCACT estimated that $13 billion in payroll taxes were from unauthorized immigrant workers and their employers in 2010. Workers become eligible for Social Security benefits when they meet the insured status and age requirements specified in the Social Security Act. They become entitled to benefits when they have met all of the eligibility requirements and filed an application for benefits. Because Social Security is an earned entitlement program, there are few restrictions on benefit payments once a worker becomes entitled to benefits. The Social Security Act does prohibit the payment of benefits to individuals residing in certain countries; individuals confined to a jail, prison, or certain other public institutions for commission of a crime; most individuals removed from the United States (i.e., deported); aliens residing in the United States unlawfully; and in some cases, aliens residing outside the United States for more than six months at a time. On March 2, 2004, President George W. Bush signed into law the Social Security Protection Act of 2004 ( P.L. 108-203 , H.R. 743 ). Among other changes, P.L. 108-203 restricts the payment of Social Security benefits to certain noncitizens who file an application for benefits based on an SSN assigned on or after January 1, 2004. Specifically, a noncitizen who files an application for benefits based on an SSN assigned on or after January 1, 2004, is required to have work authorization at the time an SSN is assigned, or at some later time, to gain insured status under the Social Security program. If the individual had work authorization at some point , all of his or her covered earnings count toward insured status (and for benefit computation purposes). If, however, the individual never had authorization to work in the United States, none of his or her covered earnings count toward insured status (and therefore benefits would not payable based on his or her work record). A noncitizen who files an application for benefits based on an SSN assigned before January 1, 2004, is not subject to the work authorization requirement under P.L. 108-203 . All of the individual's Social Security-covered earnings are counted toward insured status (and for benefit computation purposes), regardless of his or her work authorization status. The treatment of earnings based on unauthorized work for Social Security purposes is often an issue when Congress considers legislation to legalize all or part of the unauthorized population residing in the United States. For example, the most recent example of a comprehensive immigration reform bill ( S. 744 as passed by the Senate in the 113 th Congress) contained provisions that would have prohibited most persons legalized under the bill from counting earnings obtained before the person legalized toward insured status under the program or for benefit computation purposes. In addition, in the 114 th Congress, H.R. 1996 would prohibit those who received work authorization under the Deferred Action for Childhood Arrivals (DACA) program from receiving SSNs and receiving Social Security benefits. The following table summarizes the treatment of earnings based on unauthorized work for Social Security purposes under current law. The treatment of earnings based on unauthorized work for Social Security purposes differs, depending on whether an individual was assigned an SSN before 2004, or in 2004 or later. The policy with respect to SSN assignment for noncitizens was changed in late 2003. Noncitizens authorized by DHS to work in the United States can be assigned an SSN. Noncitizens not authorized to work can be assigned an SSN for a valid nonwork reason. Following a regulatory change that went into effect in late 2003, the only valid nonwork reason for assignment of an SSN would be if an individual needs an SSN to receive federal, state, or local government benefits to which he or she has otherwise established entitlement (see 20 C.F.R. §422.104). Before the regulatory change, the policy for assignment of nonwork SSNs was less restrictive, and noncitizens could be assigned an SSN for a variety of nonwork purposes, such as to obtain a driver's license. (For more information on the assignment of SSNs to noncitizens, see " Social Security Cards and Noncitizens " section.) Section 202(y) of the Social Security Act requires noncitizens in the United States to be "lawfully present" to receive benefits. If a noncitizen is entitled to benefits, but does not meet the lawful presence requirement, his or her benefits are suspended. In such cases, a noncitizen may receive benefits while residing outside the United States (including benefits based on work performed in the United States without authorization) if he or she meets one of the exceptions to the alien nonpayment provision under Section 202(t) of the Social Security Act. Under the alien nonpayment provision, a noncitizen's benefits are suspended if he or she remains outside the United States for more than six consecutive months, unless one of several broad exceptions is met. For example, an alien may receive benefits outside the United States if he or she is a citizen of a country that has a social insurance or pension system that pays benefits to eligible U.S. citizens residing outside that country (a "social insurance country"), or if he or she is a resident of a country with which the United States has a totalization agreement (see Table 1 ). If an alien does not meet one of the exceptions to the alien nonpayment provision, his or her benefits are suspended beginning with the seventh month of absence and are not resumed until he or she returns to the United States lawfully for a full calendar month.