Congress's interest in the receipt of government assistance by noncitizens dates back to at least 1882, when the country's first general immigration law excluded aliens who were deemed "likely to become a public charge" after they came to the United States. The term public charge has historically meant persons who are "primarily dependent upon the government for subsistence," and the 1882 measure effectively limited aliens' receipt of government assistance by barring aliens who were likely to substantially rely upon such assistance from entering the United States. Since that time, Congress has returned periodically to the topic of noncitizens' eligibility for public benefits, sometimes restricting noncitizens' eligibility for public benefits and sometimes expanding it. Congressional interest has been particularly high in recent years due to the sizable number of aliens who are unlawfully present in the United States (i.e., entered without inspection, or overstayed or otherwise violated the terms of their visas). Some have suggested that noncitizens' eligibility for public benefits is a "magnet" for unauthorized immigration and ought to be further restricted. Others have sought to expand at least certain aliens' eligibility for public benefits on humanitarian or public interest grounds. Whether and when persons who are present in the United States, but not U.S. citizens or nationals, may receive particular types of government assistance can be difficult to ascertain because of the various federal, state, and local laws governing their eligibility for such assistance. The Personal Responsibility and Work Opportunity Reconciliation Act of 1996 (PRWORA) was enacted to establish "national policy with respect to welfare and immigration." With certain exceptions, PRWORA bars aliens who are not "qualified aliens" from receiving federal, state, or local "public benefits," and precludes qualified aliens from receiving federal "means-tested public benefits" for 5 or more years after they enter the United States in a qualified status. However, there are also a number of other federal, state, and local measures adopted prior to, or after, the enactment of PRWORA, some of which make different provisions for noncitizens' eligibility for particular benefits. The applications of these measures can raise complicated issues of constitutional law, statutory interpretation, and administrative law. This report provides an overview of PRWORA and illustrative pre- and post-PRWORA enactments regarding noncitizen eligibility for public benefits as background, before turning to a discussion of the major legal issues raised by such measures. The discussion of enactments other than PRWORA and the legal issues they raise is selective. The report does not attempt to identify all legal measures that might affect noncitizens' eligibility for particular benefits, or all legal issues that could potentially be raised. Rather, its focus is upon illustrative measures, and major legal issues that have recurred. The report also does not address legal issues that could potentially be raised by noncitizens' receipt of public benefits, particularly whether the receipt of such benefits may result in aliens being found to be inadmissible or deportable on public charge grounds. A separate report, CRS Report R43220, Public Charge Grounds of Inadmissibility and Deportability: Legal Overview , by [author name scrubbed], discusses these issues. There are also several CRS reports addressing policy issues related to noncitizens' eligibility for public benefits. PRWORA, as amended, establishes certain default rules regarding noncitizens' eligibility for federal, state, and local public benefits by creating various categories of aliens and benefits, and prescribing when particular aliens may receive certain benefits. However, numerous measures had been enacted prior to PRWORA, which PRWORA effectively nullified or modified. In addition, Congress, states and, in some cases, localities have enacted additional measures post-PRWORA that either expand, or restrict, noncitizens' eligibility for particular benefits. Prior to the enactment of PRWORA, there generally were no overarching rules regarding noncitizens' eligibility for public benefits. Rather, individual statutes generally governed noncitizens' eligibility for benefits provided pursuant to the statute, and often classified aliens in terms of categories specific to the statute. For example, the Unemployment Compensation Amendments of 1976 expressly prohibited the payment of unemployment insurance on the basis of services performed by an alien unless the alien was (1) a lawful permanent resident (LPR) when the services were performed; (2) "lawfully present" for purposes of performing the services; or (3) residing in the United States "under color of law" when the services were performed. Noncitizens not belonging to one of these three classes—most notably, aliens who were unlawfully present or working in the United States when they provided the services upon which compensation would be based—were barred from receiving unemployment insurance. The Social Security Amendments of 1965 similarly provided that Every individual who (1) has attained the age of 65, and (2) (A) is a resident of the United States, and is either (i) a citizen or an alien lawfully admitted for permanent residence who has resided in the United States continuously during the 5 years immediately preceding the month in which he applies for enrollment under this part ... is eligible to enroll in the [Medicare Part B] insurance program. Here, the only noncitizens eligible for Medicare Part B were LPRs who had resided in the United States "continuously" for the five years prior to applying for enrollment. All others were excluded, including LPRs who had not yet resided in the United States for five years, or whose total period of residence, while longer than five years, had not been "continuous." In yet other cases, the statute was silent as to noncitizens' eligibility for benefits provided pursuant to the statute (e.g., school lunch and nutrition, supplemental food program for women, infants, and children (WIC), earned income credit), which was often taken to mean that noncitizens were not barred from receiving such benefits. In a few cases, however, states, in particular, enacted measures that addressed noncitizens' eligibility for public benefits more broadly. Perhaps the best known of these was California's Proposition 187, adopted by voters in 1994, and described by some commentators as the "impetus" for PRWORA. Proposition 187 was intended to "prevent illegal aliens in the United States from receiving benefits or public services in the State of California." Among other things, Proposition 187 barred the provision of "public social services" and "publicly-funded health care services" to persons who were not U.S. citizens, LPRs, or "admitted lawfully for a temporary period of time." It also barred persons who were not citizens, LPRs, or "otherwise authorized under federal law to be present in the United States" from admission to public elementary, secondary, and postsecondary schools. However, these and other provisions of Proposition 187 were found to be preempted by federal law, or otherwise impermissible, and not enforced. Some of these pre-PWRORA laws remain on the books, but their implementation has generally been shaped by the subsequent enactment of PRWORA. As discussed below, PRWORA "effectively invalidated all existing" federal, state, or local measures governing noncitizens' eligibility for public benefits, replacing them with default rules that states, in particular, may opt out of only in specified circumstances (e.g., by enacting a measure subsequent to PRWORA that "affirmatively provides" for unauthorized aliens' eligibility). PRWORA has, thus, resulted in unauthorized aliens being ineligible for various state services. The U.S. Department of Education similarly modified its guidance regarding which noncitizens are eligible for federal financial aid under the Higher Education Act after PRWORA's enactment. Congress enacted PRWORA in 1996, in part, to bring a degree of uniformity to noncitizens' eligibility for federal, state, and local public benefits. When enacting PRWORA, Congress provided that the restrictions and conditions it imposed apply "[n]otwithstanding any other provision of law," except as otherwise provided in PRWORA. This language has been construed to mean that PRWORA generally "invalidated" or rendered unenforceable preexisting federal, state, and local measures, at least to the degree that these measures were inconsistent with PRWORA. Then, in place of these varied measures—which often had their own ways of describing both categories of noncitizens and particular types of benefits—PRWORA established standardized taxonomies of aliens and benefits. It also prescribed general rules regarding when particular aliens are eligible for specific benefits. Under PRWORA, aliens are divided into two basic categories: qualified and not qualified. PRWORA defines qualified alien to encompass: LPRs; aliens granted asylum; refugees; aliens paroled into the United States for a period of at least one year; aliens whose deportation is being withheld; aliens granted conditional entry; and Cuban and Haitian entrants. However, certain aliens who have been subject to domestic violence are also treated as qualified aliens for purposes of PRWORA. All other aliens are not qualified. This includes those who are unlawfully present; have been granted temporary protected status, deferred enforced departure, or deferred action; or are lawfully present in the United States on nonimmigrant visas. PRWORA similarly categorizes benefits as: federal public benefits, federal means-tested public benefits, and state and local public benefits. With certain exceptions, it defines federal and state and local public benefit s to mean the following: any grant, contract, loan, professional license, or commercial license provided by [a government] agency ... or by appropriated funds ...; and any retirement, welfare, health, disability, public or assisted housing, postsecondary education, food assistance, unemployment benefit, or any other similar benefit for which payments or assistance are provided to an individual, household, or family eligibility unit by [a government] agency ... or by appropriated funds. In contrast, federal means-tested public benefit is not affirmatively defined by PRWORA, although certain benefits are expressly excluded from the application of this term (e.g., short-term, non-cash, in-kind emergency disaster relief). Because this term is not defined, PRWORA has generally been seen as granting federal agencies discretion to designate which public benefits are federal means-tested ones. As is discussed below, the Office of Legal Counsel at the Department of Justice has opined that agency interpretations of this term as encompassing only Medicaid, food stamps, supplemental security income (SSI), Temporary Assistance to Needy Families (TANF), and the State Child Health Insurance Program (SCHIP) are entitled to deference. PRWORA itself does not address state means-tested public benefits, beyond providing that affidavits of support provided by aliens' sponsors may be enforceable by any state or locality that provides "means-tested public benefit[s]" to the alien. PRWORA relies upon the taxonomies of aliens and benefits that it creates in prescribing specific rules regarding which aliens are eligible for particular benefits. The "default" rules established by PRWORA are arguably simple (although, particularly as amended, PRWORA provides for numerous exceptions ). First, aliens who are not qualified aliens are generally barred from receiving public benefits. Such aliens are not eligible for federal, state, or local public benefits (means-tested or otherwise). However, states and localities may furnish public benefits to unauthorized aliens if the state enacts legislation subsequent to PRWORA's enactment that "affirmatively provides" for their eligibility. Second, even aliens who are qualified aliens are generally subject to significant restrictions on their eligibility for SSI, TANF, Medicaid, food stamps, social services block grants, and other means-tested public benefits. Such aliens are barred from receiving federal means-tested public benefits for five years after their entry into the United States in a qualified status. In addition, certain qualified aliens are ineligible for SSI, TANF, Medicaid, food stamps, and social services block grants unless they have worked, or can be credited with, 40 qualifying quarters of work under the Social Security Act, and did not receive any federal means-tested public benefits during that time. Moreover, in determining qualified aliens' eligibility for means-tested benefits, the income and resources of the aliens' sponsor may be attributed to the alien until the alien naturalizes or has worked 40 quarters. PRWORA's "national policy with respect to welfare and immigration" is, however, subject to numerous exceptions. Some of these exceptions are incorporated into PRWORA, as amended. Others, however, exist because PRWORA grants states the authority to make various determinations affecting noncitizens' eligibility for federal, state, and local public benefits. Specifically, PRWORA permits (but does not require) states to determine, with certain exceptions and subject to certain restrictions, the eligibility of qualified aliens for TANF, social services block grants, and Medicaid, and for state public benefits; limit aliens' eligibility for "programs of general cash public assistance" furnished by states or localities, provided that any such limitations are not more restrictive than the limitations imposed under comparable federal programs; attribute the income and resources of the alien's sponsor(s) to the alien when determining aliens' eligibility for state public benefits; and provide state and local benefits to unauthorized aliens by enacting a measure subsequent to PRWORA's enactment that provides for such eligibility. As discussed later, these provisions, permitting a range of state actions, have played a significant role in certain courts' finding that PRWORA does not provide a "uniform rule" for states to follow, such that challenged state measures enacted pursuant to it are reviewed more deferentially than other state measures classifying persons on the basis of alienage. PRWORA has been amended periodically since its enactment to further clarify Congress's intent, as well as to permit certain noncitizens who were ineligible for particular benefits under PRWORA to receive such benefits. For example, the Illegal Immigration Reform and Immigrant Responsibility Act (IIRIRA) of 1996, enacted a little over a month after PRWORA, added a provision apparently intended to deter states from using their authority under PRWORA to grant in-state tuition to unauthorized aliens. This provision bars states from providing "postsecondary education benefits" to unauthorized aliens based on the alien's residence within the state unless other citizens or nationals are eligible for such benefits, regardless of their state of residence. IIRIRA also made certain other amendments to PRWORA, including by providing that certain victims of domestic violence are deemed qualified aliens for purposes of PRWORA. Other measures enacted in 1997 and in 1998 similarly amended PRWORA to permit some aliens to receive benefits they could not have received under PRWORA, as originally enacted. Congress has also enacted legislation that addresses noncitizens' eligibility for particular benefits separate and apart from PRWORA, in many cases making noncitizens eligible for benefits that would be denied to them under PRWORA's default rules. For example, Section 214 of the Children's Health Insurance Program Reauthorization Act of 2009 (CHIPRA) grants states the option to provide Medicaid and CHIP coverage to all children and pregnant women "who are lawfully residing in the United States … and who are otherwise eligible for such assistance." The phrase "lawfully residing in the United States" has been construed to include certain aliens who are not qualified aliens for purposes of PRWORA, such as lawful nonimmigrants, as well as those with temporary protected status, under deferred enforced departure, in deferred action status, or whose visa petitions have been approved and have a pending application for adjustment of status. The Patient Protection and Affordable Care Act (ACA) of 2010 similarly permits persons who are "lawfully present" to participate in certain health care programs established under the act. Lawfully present for purposes of ACA has generally been construed in the same way as lawfully residing for purposes of CHIPRA (i.e., including those with temporary protected status or under deferred enforced departure), although beneficiaries of Deferred Action for Childhood Arrivals (DACA) have been viewed as ineligible for certain benefits under ACA. States, in particular, have also enacted a number of post-PRWORA measures addressing noncitizens' eligibility for public benefits. Some of these measures were expressly authorized by PRWORA, and make aliens eligible for state and local benefits that they would otherwise be denied. Others restrict qualified aliens' eligibility for TANF, Medicaid, and social services block grants, as permitted by PRWORA. In yet other cases, however, states and localities have enacted measures that would define public benefit more broadly than PRWORA does, and seek to bar unauthorized aliens, in particular, from receiving such benefits. For example, the City of Farmers Branch, Texas, attempted to characterize residential occupancy licenses as "public benefits" when barring persons from renting housing to unauthorized aliens. The State of Georgia relied upon a similarly broad definition of public benefit —including adult education; business, gaming, and professional licenses; registration of regulated businesses; state identification cards; and tax certificates required to conduct commercial businesses—when proscribing the provision of public benefits to unauthorized aliens. More recently, Montana voters adopted a referendum which prohibits the provision of "state services" to unauthorized aliens, and defines this term to encompass cash payments, state licenses or permits, enrollment at state public universities, and services for crime victims and persons with physical disabilities. Construing and applying PRWORA and related measures to determine whether individual aliens are eligible for particular benefits can raise a number of legal issues, including (1) the constitutional rights of aliens; (2) whether federal law preempts state or local measures; and (3) whether particular types of government assistance constitute benefits under particular definitions of this term. In particular, questions regarding noncitizens' rights to equal protection and preemption are particularly likely to arise in facial challenges seeking to invalidate particular measures. Questions regarding what constitutes a benefit , in contrast, tend to occur in challenges to applications of particular measures. The constitutional guarantee of equal protection applies to all "persons" within the United States, including aliens (regardless of their immigration status). Thus, measures governing eligibility for public benefits could potentially be subject to legal challenges if they treat aliens differently than citizens. The level of scrutiny applied by the courts in reviewing challenges to such measures frequently determines whether the law is upheld, or struck down. With "rational basis review," the challenged measure will generally be upheld if it is a rational means of promoting a legitimate government objective. The measure is "presumed constitutional," and the persons challenging the law have the burden of negating all possible rational justifications for the classification. In contrast, with "strict scrutiny," the challenged measure will be upheld only if the government can demonstrate that the measure is necessary to achieve a compelling interest, and has been narrowly tailored to achieve that interest. Other "intermediate" degrees of scrutiny are also possible, depending upon the persons and rights affected by the challenged measure. Because Congress's plenary power over immigration permits it to enact measures as to aliens that would be unconstitutional if applied to citizens, federal restrictions on noncitizens' eligibility for public benefits are subject to rational basis review, and have generally been upheld. For example, in its 1976 decision in Mathews v. Diaz , the Supreme Court upheld a federal law that barred LPRs who had not resided in the United States for five years from enrolling in Medicare Part B, because it viewed the measure as a valid exercise of the federal government's authority to regulate the entry and residence of aliens, not as "irrational." In particular, the Mathews Court noted that Congress could have reasonably determined that the strength of the aliens' ties to the United States increases over their time here, and that "as the alien's tie grows stronger, so does the strength of his claim to an equal share of the munificence." The Court further suggested that Congress could have considered the "fiscal integrity" of the benefits program in drawing this line. More recently, lower courts have upheld under rational basis review PRWORA's restrictions on the receipt of federal means-tested public benefits by qualified aliens who have not resided in the United States in that status for the requisite period of time. In so doing, the courts have rejected the argument that, as a welfare statute, PROWRA was not enacted pursuant to Congress's plenary power over immigration and, thus, should be subject to more stringent review. Courts have further noted that, while a five-year bar on qualified aliens' eligibility for certain benefits is "arbitrary," as the plaintiffs asserted, this does not invalidate the measure. Rather, "cutoff dates inevitably lead to persons 'who have an almost equally strong claim to favored treatment being placed on different sides of the [eligibility] line.'" The situation as to state and local measures is more complicated, with the level of scrutiny applied in challenges to such measures generally depending upon the persons and rights affected by the measure. There is no fundamental right to receive public benefits. Rather, receipt of benefits falls within the "area of economics and social welfare," and classifications affecting such interests, standing alone, are generally subject to rational basis review. However, courts also give heightened scrutiny to measures involving "suspect classifications," regardless of whether a fundamental right is involved, and classifications based on alienage are suspect. Thus, because states and localities lack the federal government's plenary power over immigration, certain state and local measures restricting noncitizens' eligibility for public benefits—particularly measures restricting LPR's eligibility—have been subject to strict scrutiny. In its 1971 decision in Graham v. Richardson , for example, the Supreme Court struck down Pennsylvania and Arizona laws that barred or limited receipt of state "general assistance" by LPRs. In so doing, the Court expressly rejected the argument that states have a "special public interest" in favoring their own citizens over aliens in the distribution of limited resources such as welfare benefits. The Graham Court also emphasized that LPRs, like citizens, may live and work in a state for many years, contributing to its economic growth. Courts have, however, declined to apply strict scrutiny to state measures that exclude aliens, even long-term "permanent resident" aliens with significant ties to the United States, from employment involving "political and governmental functions." Instead, courts have applied rational basis review to such measures on the grounds that states must have the power to "preserve the basis conception of a political community" for a democracy to function. Certain states have recently enacted measures that would define public benefits or state services in such a way as to encompass employment with state or local governments, and denials of certain employment pursuant to such measures could potentially be subject to more lenient review than denials of other benefits. Courts have also declined to view unauthorized aliens as a suspect classification on the grounds that "their presence in this country in violation of federal law is not a 'constitutional irrelevancy.'" This means that state and local measures denying benefits to unauthorized aliens are generally subject to more deferential review than measures denying benefits to LPRs, such as the state laws at issue in Graham . However, state and local measures denying particularly significant benefits to certain unauthorized aliens could potentially be subject to heightened scrutiny. Most notably, in its 1982 decision in Plyler v. Doe , the Supreme Court struck down a Texas statute which prohibited the use of state funds to provide elementary and secondary educations to children who were not "legally admitted" to the United States on the grounds that the statute did not further a "substantial" state goal. While noting that education did not constitute a fundamental right, the Court distinguished it from other benefits, describing primary and secondary education as of "supreme importance" in preserving a democratic system of government. The Court further noted that denying public elementary and secondary educations to unauthorized alien children would contribute to the formation of a permanent underclass, which the Fourteenth Amendment was designed to prevent. Lower courts have reached similar conclusions as to Proposition 187's denial of public elementary and secondary educations to unauthorized alien children, and certain Alabama requirements regarding verification of the citizenship and immigration status of students enrolling in public elementary and secondary schools. The Plyler Court also suggested, however, that state and local measures classifying persons on the basis of alienage could potentially enjoy more deferential review if Congress has "by uniform rule prescribed what it believes to be appropriate standards for the treatment of an alien subclass." Following PRWORA's enactment, questions have arisen as to whether PRWORA provides such a uniform rule, as discussed below. If it does, state and local measures that follow this rule could potentially be subject to rational basis review, like federal measures, and thus more likely to withstand legal challenges. Similarly, several courts and commentators have noted that the Supreme Court precedents applying strict scrutiny to measures classifying persons on the basis of alienage all arose from challenges brought by LPRs (i.e., lawful immigrants ). Some have suggested that classifications affecting lawful nonimmigrants (i.e., aliens lawfully permitted to remain in the country on a temporary basis) might be subject to less stringent review, regardless of whether PRWORA provides a uniform rule, as is also discussed below. Courts have reached differing conclusions about whether PRWORA provides a uniform rule regarding noncitizens' eligibility for public benefits, like that contemplated in Plyler . Some courts, including one federal appellate court, have suggested that it does. In its 2004 decision in Soskin v. Reinertson , the U.S. Court of Appeals for the Tenth Circuit ("Tenth Circuit") characterized the state law in question—which repealed optional state-funded Medicaid coverage for certain aliens—as "addressing the Congressional concern (not just a parochial state concern) that 'individual aliens not burden the public benefits system.'" The Tenth Circuit further noted that, although PRWORA expressly authorizes states to make a number of determinations affecting noncitizens' eligibility for public benefits, it "does not give the states unfettered discretion. Some coverage must be provided to aliens; some coverage is forbidden. State discretion is limited to the remaining optional range of coverage." Previously, in its 1999 decision in Cid v. South Dakota Department of Social Services , the Supreme Court of South Dakota had reached a similar conclusion, finding that an administrative rule which terminated certain noncitizens' eligibility for benefits did not conflict with national policies regarding aliens, and placed no burdens on aliens other than those contemplated by federal law. Other courts, in contrast, have found that PRWORA does not establish a uniform rule that permits states to classify persons on the basis of alienage when providing public benefits. New York's highest state court reached this conclusion in its much-cited 2001 decision in Aliessa v. Novello . There, the court applied strict scrutiny in reviewing a challenge to a state law that barred the provision of state-funded Medicaid coverage to lawfully present aliens who were not qualified aliens for purposes of PRWORA, as well as to qualified aliens who had not resided in the United States for five years. The court did so because it did not view PRWORA's provisions regarding aliens' eligibility for public benefits as reflecting "a uniform national policy." Rather, according to the Aliessa court, [PRWORA] expressly authorizes States to enact laws extending "any State or local public benefit" even to those aliens not lawfully present within the United States ... The converse is also true and exacerbates the lack of uniformity: ... subject to certain exceptions, States are authorized to withhold State Medicaid from even those qualified aliens who are eligible for Federal Medicaid under PRWORA. Thus, in administering their own programs, the States are free to discriminate in either direction—producing not uniformity, but potentially wide variation based on localized or idiosyncratic concepts of largesse, economics and politics. Maryland's highest court took a similar view in its 2006 decision in Ehrlich v. Perez . There, the court applied strict scrutiny in invaliding a state budget measure that did not appropriate funds for the State Medical Assistance Program for resident alien children and pregnant women who immigrated to the United States on or after PRWORA's enactment, but funded the same benefits for citizens and resident aliens who arrived before that date. The state argued that this was permissible, because Congress had prescribed "a uniform rule for the treatment of an alien sub-class in regard to the provision of medical benefits." The court, however, disagreed, finding that PRWORA did not prescribe a uniform rule. The court further suggested that it was not inclined to view as compelling the alleged government interests that PRWORA recognized as such (i.e., enacting new rules for eligibility and sponsorship agreements in order to assure that aliens are self-reliant in accordance with national immigration policy, and removing the incentive for illegal immigration provided by the availability of public benefits). It also suggested that, even if PRWORA had prescribed a uniform rule, state measures that classify persons on the basis of alienage would remain subject to strict scrutiny because Congress cannot authorize the states to violate the constitutional guarantee of Equal Protection. It is important to note, however, that the structure of the programs in question, as well as the framing of the issues by the litigants, can substantially affect the outcome in such cases. Several courts have, for example, recently suggested that the repeal of state programs that had benefited qualified aliens who were ineligible for federal means-tested public benefits because they had not been present in the United States in a qualified status for the requisite period of time are not subject to strict scrutiny, so long as (1) the beneficiaries of the state program are exclusively aliens, and (2) the only comparable programs benefitting citizens are federal ones. The U.S. Court of Appeals for the Ninth Circuit (Ninth Circuit), for example, found that the noncitizens challenging the repeal of a Washington law failed to raise an equal protection claim, since they had failed to show that the state had "treated the plaintiff[s] differently from similarly situated individuals." Because there were no similarly situated individuals, the Ninth Circuit rejected plaintiffs' Equal Protection challenge without subjecting the repeal measure to either strict scrutiny or rational basis review. Other courts, however, have applied rational basis review in upholding similar measures, sometimes on the grounds that rational basis review should govern state measures that repeal (as opposed to create) programs that benefited only aliens. In other cases, the court has suggested that rational basis review is appropriate so long as the measure only distinguishes between classes of aliens, and does not distinguish between aliens and citizens. Questions have also been raised recently regarding the level of scrutiny to be applied to state and local measures denying lawful nonimmigrants drivers or occupational licenses, which constitute benefits under certain definitions of this term. Many of the Supreme Court and other cases discussed previously, scrutinizing state and local benefits measures, involved LPRs (i.e., lawful immigrants , many of whom reside and work in the United States for extended periods of time). Far fewer challenges have involved aliens lawfully admitted to the United States as nonimmigrants (such as guestworkers), and two federal courts of appeals expressly noted the lack of Supreme Court precedent applying strict scrutiny to measures affecting nonimmigrants in finding that such measures are subject to a lower level of scrutiny than that given to measures affecting LPRs. In its 2005 decision in LeClerc v. Webb, the U.S. Court of Appeals for the Fifth Circuit (Fifth Circuit) upheld a Louisiana law that prohibited lawful nonimmigrants from sitting for the state bar exam, in part, because it viewed "rational basis review ... [as] the appropriate standard for evaluating state law classifications affecting nonimmigrant aliens." In so doing, the Fifth Circuit distinguished an earlier case, In re Griffiths , wherein the Supreme Court invalidated a Connecticut law that conditioned bar admission on U.S. citizenship, on the grounds that the plaintiffs in Griffiths were LPRs, and the Supreme Court "ha[s] never applied strict scrutiny review to a state law affecting ... other alienage classifications." In particular, the Fifth Circuit found that LPRs are distinguishable from lawful nonimmigrants because LPRs are unable to "exert political power in their own interest given their status as virtual citizens," while lawful nonimmigrants' lack of legal capacity is "tied to their temporary connection to this country." The Fifth Circuit also found that, while LPRs can be said to be "similarly situated" to citizens in their economic, social and civic conditions, lawful nonimmigrants are not. The Fifth Circuit noted, among other things, that lawful nonimmigrants may not serve in the U.S. military, are subject to strict restrictions on employment, and incur different tax treatment than citizens and LPRs. The Fifth Circuit relied upon similar reasoning in its 2011 decision in Van Staden v. St. Martin , upholding a Louisiana law that barred lawful nonimmigrants from obtaining practical nursing licenses. The U.S. Court of Appeals for the Sixth Circuit (Sixth Circuit) reached a similar conclusion in its 2007 decision in League of United Latin American Citizens [LULAC] v. Bredesen . There, in upholding a Tennessee law that permitted lawful nonimmigrants to obtain only "certificates for driving," not driver's licenses, the Sixth Circuit observed that "lawful permanent residents are the only subclass of aliens who have been treated as a suspect class." Like the Fifth Circuit, the Sixth Circuit noted that the Supreme Court had never applied strict scrutiny to a state or local measure affecting aliens who were not LPRs, and found that lawful nonimmigrants differ from LPRs in ways which suggest that the traditional rationale for applying strict scrutiny to measures affecting LPRs (i.e., their similarity to citizens) might not apply to measures affecting lawful nonimmigrants. The Sixth Circuit further found that the Tennessee law withstood rational basis review since it "was designed to serve homeland security interests by indicating to third parties that the State of Tennessee does not vouch for the identity of the person holding a certificate for driving while at the same time allowing the holder of the certificate to validly operate a motor vehicle in Tennessee," and the plaintiffs had failed to show why these restrictions are not rationally related to a legitimate government interest. Most recently, however, the U.S. Court of Appeals for the Second Circuit (Second Circuit) reached the opposite conclusion in its 2012 decision in Dandamudi v. Tisch , applying strict scrutiny to strike down a New York law that permits only U.S. citizens and LPRs to become licensed pharmacists. The Second Circuit reached this conclusion, in part, because it viewed Supreme Court precedent as recognizing only two circumstances in which state and local classifications based on alienage are not subject to strict scrutiny: namely, (1) when a state excludes aliens from political and governmental functions; and (2) when a state denies certain benefits to unauthorized aliens. It thus declined to recognize a third exception for measures involving aliens who are not LPRs, although it acknowledged that the Supreme Court had "never explicitly applied strict scrutiny review to a statute discriminating against nonimmigrant aliens." The Second Circuit also rejected the reasoning applied by the Fifth and Sixth Circuits, particularly their grounds for distinguishing lawful nonimmigrants from LPRs. According to the Second Circuit, lawful nonimmigrants are, in practice, no different than LPRs in that they often live and work in the United States for extended periods of time. Relatedly, the Second Circuit noted that the purported "transience" of nonimmigrant aliens does not provide a compelling justification for barring nonimmigrants from obtaining pharmacist licenses and practicing in the state, since "[c]itizenship and Legal Permanent Residency carry no guarantee that a citizen or LPR professional will remain in New York ..., have funds available in the event of malpractice, or have the necessary skill to perform the task at hand." While these decisions all focus upon licenses, they could have potentially significant implications for state and local measures regarding noncitizens' eligibility for public benefits more generally. Certain states, in particular, have adopted definitions of public benefits or related terms that would encompass drivers' licenses or occupational and professional licenses. However, PRWORA expressly exempts professional and commercial licenses for nonimmigrants whose visas are related to employment in the United States from its definition of public benefits , which would appear to limit the ability of states and localities to assert that they are complying with a "uniform rule" established by the federal government when restricting nonimmigrants' ability to obtain occupational and professional licenses. To the contrary, an argument could potentially be made that, to the degree that the state or locality purports to deny an occupational or professional license to an alien whom the federal government admitted to work in a particular field, the state or local measure is preempted by federal law. In fact, the Second Circuit indicated that it viewed the New York law as "stand[ing] as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress." However, its holding in Dandamudi was not based on preemption since some plaintiffs had "TN status" created pursuant to the North American Free Trade Agreement (NAFTA), and only the federal government may bring suit challenging state laws inconsistent with NAFTA. State and local measures concerning noncitizens' eligibility for public benefits can raise questions of preemption, because the Supremacy Clause of the U.S. Constitution establishes that federal law, treaties, and the Constitution itself are "the supreme Law of the Land, ... any Thing in the Constitution or Laws of any state to the Contrary notwithstanding." In particular, the Constitution entrusts Congress with the power to regulate immigration. This means that state or local measures that purport to regulate immigration—by determining which aliens may enter or remain in the United States, or the terms of their continued presence—are, per se , preempted, regardless of whether Congress has legislated on the matter. Other measures, which affect aliens, but do not constitute regulation of immigration, could also be found to be preempted, depending upon the scope of any congressional enactments. Specifically, federal statutes may preempt state and local measures in one of three ways: (1) the statute expressly indicates its preemptive intent (express preemption); (2) a court concludes that Congress intended to occupy the regulatory field, thereby implicitly precluding state or local action in that area (field preemption); or (3) state or local action directly conflicts with or otherwise frustrates the purpose of the federal scheme (conflict preemption). Preemption claims have recently been raised in response to state and local measures that would define benefits broadly and bar the provision of benefits to unauthorized aliens. The Supreme Court distinguished between impermissible regulations of immigration, and permissible measures affecting aliens, in its 1976 decision in De Canas v. Bica . There, in reversing and remanding a state court decision finding that a California law which prohibited the knowing employment of unauthorized aliens was preempted, the Court noted that the fact that aliens are the subject of a state statute does not render it a regulation of immigration, which is essentially a determination of who should or should not be admitted into the country, and the conditions under which a legal entrant may remain. ... In this case, California has sought to strengthen its economy by adopting federal standards in imposing criminal sanctions against state employers who knowingly employ aliens who have no federal right to employment within the country; even if such local regulation has some purely speculative and indirect impact on immigration, it does not thereby become a constitutionally proscribed regulation of immigration. Subsequent decisions have generally followed De Canas , striking down state and local measures that are seen as determining who should be admitted to the country, or the conditions under which entrants may remain, and reviewing other measures affecting aliens within the context of congressional enactments, as discussed below. However, courts have reached differing conclusions as to what types of measures are to be seen as determining who may be admitted to the country or the conditions under which they may remain. In several cases, state or local measures that would deny benefits to certain noncitizens have been found to be preempted regulations of immigration because they would create their own categories for classifying aliens, or would involve state and local officials in determining aliens' status. For example, the provisions of California's Proposition 187 restricting noncitizens' eligibility for "public social services" and "publicly-funded health care services," discussed previously, were initially struck down on these grounds. In particular, the reviewing court noted that, by categorizing persons as citizens, LPRs, or "admitted lawfully for a temporary period of time," Proposition 187 "created its own scheme setting forth who is, and who is not, entitled to be in the United States" that "is not in any way tied to federal standards." According to the court, the creation of this independent scheme constituted a regulation of immigration because it was tantamount to determining which aliens may enter and the conditions on which they may remain. The court similarly viewed Proposition 187's requirement that state officials "make independent determinations as to whether a person is deportable under federal law" as a regulation of immigration, since it, too, would have involved the state in determining who may be admitted to and remain in the country. Subsequent state or local measures have similarly been found to be preempted because they created their own classifications of aliens and/or authorized state or local officials to determine aliens' status, including an Alabama law that prohibited various categories of aliens from attending public post-secondary institutions of higher education, and a Montana law that barred "illegal aliens" from receiving state services. There is less agreement as to whether measures that would deny benefits to noncitizens, but do not involve state or local classifications or determinations of aliens' status, are regulations of immigration. Some courts have suggested that they are on the grounds that aliens are effectively excluded from jurisdictions where they cannot obtain necessary benefits. Other courts, however, have held that the denial of benefits can only be said to have a "purely speculative and indirect impact on immigration," and thus does not constitute a regulation of immigration under De Canas . Yet other courts have found that, while the denial of benefits, in itself, is generally not a regulation of immigration, the denial of benefits that significantly affect noncitizens' ability to obtain housing within the jurisdiction should be viewed as such. One federal district court, for example, found that, while the local ordinance in question was "grounded in federal immigration classifications ..., ... it use[d] those classifications for purposes not authorized or contemplated by federal law" when attempting to deny residential occupancy licenses to aliens who were not lawfully present. Measures that are not per se preempted as regulations of immigration can also be challenged on the grounds that they are expressly or impliedly preempted by federal statute. The outcome in such cases can vary considerably, depending upon the terms of the state or local measure, and the provisions of the federal statute that allegedly preempts it. However, certain issues have been litigated with some frequency, and often addressed in similar fashion by the courts. For example, the provisions of the Immigration and Nationality Act (INA) barring the employment of unauthorized aliens have generally not been seen as preempting such aliens' eligibility for public benefits and, particularly, their recovery of workers' compensation. Similarly, the INA's provisions regarding alien harboring have not been seen as preempting state and local measures (enacted pursuant to PRWORA) providing benefits to unauthorized aliens. Nor has the INA's provisions regarding nonimmigrant visas (particularly student visas) been seen as preempting state measures that would permit unauthorized aliens who have completed a certain number of years of secondary education within the state from obtaining in-state tuition. Courts have disagreed as to whether PRWORA constitutes a comprehensive scheme such that it could be said to have occupied the regulatory field concerning noncitizen eligibility for benefits, precluding States and localities from establishing their own eligibility standards. Some courts have suggested that it does, noting, The intention of Congress to occupy the field of regulation of government benefits to aliens is declared throughout Title IV of [PRWORA]. Whatever the level of government extending the benefits and whatever the source of the funding for the benefits—federal, state or local—they are all included within the expansive reach of [PRWORA]. The ... law includes: statements of national policy regarding the denial of public benefits to illegal immigrants ...; rules regarding immigrant eligibility for federal, state and local benefits, including definitions of the benefits covered ...; a description of state legislative options in the area of immigrant eligibility for state or local benefits ...; and a system for verifying immigration status to determine eligibility for benefits and services. Together, these provisions both demarcate a field of comprehensive federal regulation within which states may not legislate, and define federal objectives with which states may not interfere. Other courts, however, have noted the range of discretion that PRWORA left to the state, and found that PRWORA does not constitute a "comprehensive scheme," or "purport to offer a definitive approach to the problem that Congress perceived." Such courts have generally emphasized that PWRORA expressly authorizes states to enact measures making unauthorized aliens eligible for state and local benefits. In such courts' view, the fact that Congress has granted this authority to the states—with "no ... limits on the duration, extent, or quantity of state or local benefits" that may be provided—precludes a finding that Congress has impliedly preempted the field. Courts have generally also relied upon similar logic in rejecting the argument that state and local measures providing benefits to unauthorized aliens are preempted because they conflict with the stated congressional policy that "aliens within the Nation's borders not depend on public resources to meet their needs." What constitutes a benefit for purposes of particular federal, state, and local statutes can raise issues of statutory interpretation and administrative law. Statutes generally cannot address all potential circumstances wherein questions might arise about whether individual aliens are entitled to specific benefits. Thus, courts frequently must construe various statutes addressing noncitizens' eligibility for public benefits in the course of applying them in particular cases and controversies. In many cases, the court does this by relying upon the "plain meaning" rule. This rule calls for courts to look to the statutory text, as opposed to legislative history, when the meaning is clear. In other cases, the court may consult the legislative history of the statute in an attempt to determine lawmakers' intent; or resort to other canons of statutory construction. In yet other cases, the executive agency tasked with implementing the statute has, formally or informally, interpreted the statute in the course of administering it, and the court must determine what degree of deference, if any, is to be accorded to the agency's interpretation. Courts generally grant the greatest deference to agency interpretations that were adopted by an agency through notice-and-comment rulemaking, although interpretations adopted through other means may also be granted some deference. Three questions, in particular, have recurred as to noncitizens' eligibility for public benefits: (1) what constitutes a public benefit for purposes of PRWORA; (2) what does it mean for a state law to "affirmatively provide" for unauthorized aliens' eligibility for public benefits; and (3) what constitutes a federal means-tested public benefit for purposes of PRWORA. These three questions are the focus of the discussion below. However, it is important to note that PRWORA and other measures affecting noncitizens' eligibility for public benefits have also raised related questions (e.g., what it means for an alien to have entered the United States in a qualified status, what constitutes an emergency medical condition, etc.), that are outside the scope of this report. It should also be noted that identical terms can be construed differently in different provisions of law. Relatedly, courts in different jurisdictions could potentially construe the same statute differently. As previously noted, PRWORA encompasses various types of government assistance within its definitions of public benefits , including grants, contracts, loans, and professional or commercial licenses, as well as retirement, welfare, health, disability, public or assisted housing, postsecondary education, food assistance, and unemployment benefits. However, it also refers to "other similar benefit[s]," raising questions about whether particular types of assistance constitute federal, state, or local public benefits for purposes of PRWORA. Some have argued that this term be construed narrowly, as encompassing only cash payments provided directly to the alien. Others have proposed that the term be construed broadly, to encompass every function that government instrumentalities perform for persons within their jurisdictions. Courts have, to date, generally declined to adopt either of these views, instead viewing "other similar benefit[s]" as services that "assist people with economic hardship," and could potentially "create [an] incentive for illegal immigration." In County of Alameda v. Agustin , for example, the California Court of Appeals rejected the argument that "child collection support services" and the issuance of a court order requiring child support payments constituted state and local public benefits and, thus, could not be provided to an unauthorized alien in the absence of a state law that expressly provided for noncitizens' eligibility. While the court's primary rationale for reaching this conclusion was that child support payments were made from private funds, it noted the county's role in obtaining these funds, but found this role permissible given the purposes of PRWORA and the types of benefits encompassed within its definition of state and local public benefits . According to the court, PRWORA was intended to "reduce the incentive for illegal immigration by denying publicly financed social welfare benefits to aliens not residing legally in the United States." The court also noted that all the benefits listed in PRWORA are "direct income support payments" or "services intended to meet the daily needs of disadvantaged persons," and are "continuing or potentially continuing benefits, intended to provide ongoing public support for the recipients for as long as required." It viewed the child collection support services as "quite different" from the benefits listed in PRWORA because such services do not "foster[] dependence on public support." Rather, according to the court, such services are intended to help recipients support themselves, and terminate with the award of child support. Thus, the court concluded that, because child collection support services "provide no continuing public assistance to recipients" and "create little or no incentive for illegal immigration," they are not state and local public benefits for purposes of PRWORA. The court further noted that, "when properly provided, child support collection services return to the local agency considerably more funds than they cost." Other decisions by various state courts have expressly or apparently relied upon similar logic in finding that workers' compensation; benefits payable from a state fund for compensating victims of hit-and-run accidents and uninsured motorists; admission to or enrollment at public institutions of higher education (but not in-state tuition); residential occupancy licenses for renters; payment of prevailing wages; funding of an entity that provides services to day laborers ; and death benefits under federal employees' group life insurance policies do not constitute public benefits for purposes of PRWORA. However, in-state tuition and certain health programs have been found by some reviewing state courts to be public benefits. More recently, similar questions have arisen as to what it means for professional licenses to be provided by a government agency or with appropriated funds. In particular, in challenging petitions from unauthorized aliens seeking admission to the California and Florida bars, the federal government and other parties have suggested that PRWORA generally bars unauthorized aliens from receiving law licenses unless the state legislature has adopted a statute that "affirmatively provides" for their eligibility. According to this view, state high courts, which generally regulate admission to the state bar, are state agencies because they are part of the state's judicial branch. Similarly, according to this view, law licenses are provided by appropriated funds since state high courts rely, in part, on appropriated funds to finance their operations. Others, however, have argued that state courts are not state "agencies," as that term is conventionally understood, and that bar applicants pay fees for their licenses. It remains to be seen what the courts will decide, or whether administrative agencies or the courts will adopt an equally broad view of what it means for other (non-license) benefits to be provided by a government agency, or by appropriated funds. Because PRWORA bars states and localities from providing benefits to unauthorized aliens unless the state has enacted a measure that "affirmatively provides" for such eligibility, questions have also been raised about what it means to affirmatively provide for unauthorized aliens' eligibility. Some have asserted that a measure must expressly reference Section 411(d) of PRWORA (8 U.S.C. §1621(d)), and clearly specify that unauthorized aliens will be eligible, in order to affirmatively provide for such aliens' eligibility. This view is generally based on the conference report accompanying PRWORA, which states that "[o]nly the affirmative enactment of a law by a ... legislature and signed by the Governor after the date of enactment of this Act, that references this provision , will meet the requirements of this section." However, as enacted, PRWORA does not require that states refer to either Section 411, or to the aliens being unauthorized, and reviewing courts generally have found that there are no such requirements. In reaching this conclusion, the courts have noted that Congress has elsewhere required states to reference specific provisions of federal law when enacting particular measures, and PRWORA does not do this. Thus, they concluded, Congress is presumed not to have intended to impose such a requirement with PRWORA. Courts have also found that nothing in PRWORA requires states to include in any measures making unauthorized aliens eligible for public benefits language that "clearly put[s] the public on notice that tax dollars are being used to benefit illegal aliens." However, one court has suggested that a state could not be said to have "affirmatively provided" for unauthorized aliens' eligibility if it were to "confer[] a benefit generally without specifying that its beneficiaries may include undocumented aliens." This court further found that resorting to the conference report and PRWORA's legislative history in construing "affirmatively provides" is inappropriate, since the plain meaning is clear. Courts have also found that state legislatures may, consistent with Section 411 of PRWORA, delegate to administrative agencies or local governments the authority to determine whether unauthorized aliens are eligible for particular benefits. At least one court has indicated that it views the judicial branch as similarly entitled to provide for unauthorized aliens' eligibility for any "benefits" within the court's power to grant. However, PRWORA does refer to measures being "enacted," and certain parties challenging unauthorized aliens' eligibility for law licenses have asserted that, while courts could be said to "adopt" rules, they do not "enact" legislation. Some have questioned the degree of deference to be accorded to federal agency determinations regarding federal means-tested public benefits and, specifically, whether benefit programs other than the five historically recognized by the federal government ought to be included. As noted previously, PRWORA does not affirmatively define federal means-tested public benefits . Rather, it excludes certain benefits (e.g., some emergency disaster relief) from the application of the general bar upon the receipt of such benefits by qualified aliens during their first five years after entering the United States in a qualified status. Executive agencies have determined that federal means-tested public benefits means SSI, TANF, Medicaid, food stamps, and the state Child Health Insurance Program (SCHIP). As introduced in the House and Senate, PRWORA would have defined federal means-tested public benefits to mean the following: a public benefit (including cash, medical, housing, and food assistance and social services) of the Federal Government in which the eligibility of an individual, household, or family eligibility unit for benefits, or the amount of such benefits, or both are determined on the basis of income, resources, or financial need of the individual, household, or unit. However, this definition was stricken from the bill passed by the Senate because PRWORA was brought to the floor as a reconciliation bill and, as such, was subject to procedural rules allowing challenges to extraneous provisions. As used here, extraneous provisions included provisions that "produced changes in outlays or revenues which are merely incidental to the non-budgetary components of the provision." The proposed definition of federal means-tested public benefits was deemed to be extraneous because it "reached discretionary spending programs, which, in this context, lay beyond the proper scope of the reconciliation process." However, the conference report accompanying the language that was ultimately enacted as PRWORA includes a statement that the conferees intended the term federal means-tested public benefit to be construed in light of the definition given in the bill as introduced. Following PRWORA's enactment, the Departments of Health and Human Services and Housing and Urban Development proposed regulations, which other agencies either concurred in or deferred to, that construed federal means-tested public benefits as encompassing only mandatory spending programs, not discretionary ones. The Office of Legal Counsel (OLC) at the Department of Justice subsequently expressed its view that these regulations are entitled to deference, since the statutory text is ambiguous, and the agency's construction is a reasonable one. OLC acknowledged that "[s]everal aspects of the text and legislative history of [PRWORA], when viewed in isolation," could potentially be said to "support a broad[er] interpretation of 'federal means-tested public benefit' that would include discretionary programs." However, OLC found that these factors carried less weight than Congress's ultimate decision not to incorporate a definition of federal means-tested public benefits that encompassed discretionary spending programs in the text of PRWORA as enacted. In so finding, OLC cited the "well-settled canon of interpretation that 'where the final version of a statute deletes language contained in an earlier draft, [it may be presumed] that the earlier draft is inconsistent with ultimate congressional intentions." It also pointed to several provisions that had been struck from the Senate-passed version of PRWORA on the grounds that they were extraneous, and subsequently been reintroduced by the conference committee. The definition of federal means-tested public benefits was not one of these. OLC further suggested that PRWORA ought to be construed in light of the rules governing reconciliation that shaped its enactment, which foreclosed consideration, in that context, of provisions affecting discretionary spending. Following the OLC's opinion, individual agencies promulgated additional regulations identifying specific mandatory spending programs that they administered as providing federal means-tested public benefits. No court appears to have addressed the permissibility of these agency interpretations. However, as noted in OLC's opinion, any party seeking a broader (or narrower) application of the term federal means-tested public benefit in the courts could face significant legal barriers, since PRWORA does not define this term, and the agencies tasked with implementing the statute have done so by notice-and-comment rulemaking. Where Congress has not addressed the "precise question at issue," courts generally defer to "reasonable" agency interpretations. On the other hand, it should be noted that the fact that federal agencies have historically interpreted the phrase federal means-tested public benefit to mean five specific mandatory spending programs would not necessarily preclude them from interpreting the phrase differently in the future. As the foregoing discussion illustrates, noncitizen eligibility for public benefits can raise complicated legal issues in part because of the various federal, state, and local statutes regarding such eligibility, and in part because the construction and application of these statutes can raise questions of constitutional law, statutory interpretation, and administrative law. The situation does not seem likely to change in the near future. In fact, Congress has recently considered a number of changes to noncitizens' eligibility for public benefits, some intended to expand, and other to restrict, such eligibility. Issues related to noncitizens' eligibility are also being litigated in the courts, with different jurisdictions coming to sometimes different conclusions on the same question (e.g., the standard of review applicable to measures affecting nonimmigrant aliens). 

Summary: Whether and when noncitizens may receive particular types of government assistance can be difficult to ascertain because of the various federal, state, and local laws governing their eligibility for such assistance. The Personal Responsibility and Work Opportunity Reconciliation Act (PRWORA) of 1996 was enacted to establish "national policy with respect to welfare and immigration." With certain exceptions, PRWORA bars aliens who are not "qualified aliens" from receiving federal, state, or local "public benefits," and also precludes qualified aliens from receiving "federal means-tested public benefits" for five or more years after they enter the United States in a qualified status. However, there are also a number of federal, state, and local measures adopted prior to, or after, PRWORA, some of which make different provisions for noncitizens' eligibility for particular benefits. The application of these measures can raise complicated issues of constitutional law, statutory interpretation, and administrative law. The constitutional guarantee of equal protection applies to all "persons" within the United States, including aliens. Thus, measures governing eligibility for public benefits could be subject to legal challenge if they treat aliens differently than citizens. Because of Congress's plenary power over immigration, federal measures that distinguish between aliens and citizens will generally be upheld so long as they are rationally related to a legitimate government interest. State and local measures, in contrast, are generally subject to some type of heightened scrutiny, the degree of which can vary depending upon the benefit involved and the aliens' status. However, state and local measures that follow a "uniform rule" established by Congress could potentially receive the same deferential review afforded to federal measures. Courts have reached differing conclusions as to whether PRWORA establishes such a uniform rule. Courts have also disagreed as to whether measures that treat lawful nonimmigrant aliens differently from citizens are subject to the same level of scrutiny as those that distinguish between lawful immigrant aliens and citizens. Questions can also arise as to whether particular state and local measures are preempted by federal law. Some states and localities, concerned about the presence of unauthorized aliens within their jurisdiction, have recently enacted measures which would define benefits or related terms more broadly than PRWORA does, and further restrict aliens' eligibility for them. Such measures could potentially be challenged on preemption grounds because the Constitution grants Congress the power to regulate immigration. State and local measures that purport to determine the conditions upon which aliens may enter or remain in the United States are, per se, preempted. Federal statutes can also preempt state and local measures by expressly prohibiting them, containing conflicting requirements, or occupying the field. Moreover, in the application of particular measures, there have been questions about whether particular government programs, services, or types of assistance are benefits. For example, although PRWORA includes certain types of assistance within its definitions of public benefit, it also refers to "any other similar benefit." Parties have litigated whether particular assistance constitutes a benefit "similar" to those governed by PRWORA. They have also litigated whether PRWORA bars aliens from receiving benefits whose provision entails the expenditure of appropriated funds, even if the aliens themselves must pay a fee for the benefit; as well as what it means for a state to "affirmatively provide" for eligibility. Similarly, because PRWORA does not affirmatively define "federal means-tested public benefits," there has been debate about the degree of deference to be accorded to agency interpretations of this term as encompassing only five mandatory spending programs (e.g., Medicaid), and no discretionary spending programs.