The November 13, 2015, terrorist attacks in Paris have refocused attention on U.S. visa issuance and national security screening procedures that undergird the admission of foreign nationals to the United States. The visa issuance process is widely recognized as an integral part of immigration control and border security. Foreign nationals (i.e., aliens) not already legally residing in the United States who wish to come to the United States generally must obtain a visa to be admitted. The foreign national must establish that he/she is qualified for the visa under one of the various admission criteria. He or she must also establish that he/she is not ineligible for the visa due to one or more of the legal bars to admission. Applying for a visa is the first gateway for foreign nationals to seek admission to the United States, and the data collected as part of that process forms the core of the biometric and associated biographic data that the United States collects on foreign nationals. Under current law, two departments—the Department of State (DOS) and the Department of Homeland Security (DHS)—play key roles in administering the law and policies on immigration visas. DOS's Bureau of Consular Affairs (Consular Affairs) is responsible for issuing visas, DHS's Citizenship and Immigration Services Bureau (USCIS) is charged with approving immigrant petitions (and nonimmigrant petitions stateside), DHS's Immigration and Customs Enforcement (ICE) operates the Visa Security Program in selected embassies abroad, and DHS's Customs and Border Protection Bureau (CBP) is tasked with inspecting all people who enter the United States. Today's visa issuance policy dates back to 1924, when Congress first passed legislation assigning consular officers with the responsibility to approve or deny visas. The Immigration Act of 1924 codified a decree in 1917 as a consequence of World War I that proclaimed aliens must present certain documents as a prerequisite to entering the United States. When the Senate Committee on the Judiciary was tasked with investigating the immigration system in 1947, their report offered the following observation: After a study of this problem, the Congress provided in the Immigration Act of 1924 for a double check of aliens by separate independent agencies of the Government, first by consular officers before the visas were issued, and by immigration officers after the aliens reached the port of entry. If a double check was essential 25 years ago to protect the United States against criminals or other undesirables, it is the opinion of the subcommittee that it is even more necessary in the present critical condition of the world to use the double check to screen aliens seeking to enter the United States. This view prevailed in 1952 when Congress codified the various statutes on immigration and nationality into the Immigration and Nationality Act of 1952 (P.L. 82-414), which remains the basis of governing law. At its core, visa integrity protects the United States from foreign nationals who threaten public health and safety or national security, while at the same time welcomes legitimate foreign nationals who bolster the U.S. economy and foster international exchanges. Balancing these dual, and some would say competing, missions is an ongoing challenge. The policy questions center on the efficacy of the process, the security features of the policies, and whether the law needs to be revised to improve efficiency and strengthen security. The report opens with an overview of visa issuance policy. It then explains the key provisions that guide the documentary requirements and approval/disapproval process. The section on consular screening procedures includes an analysis of trends over time in denying visas. Visa revocation, a reoccurring issue of concern to Congress, and the visa security program are discussed as well. There are two broad classes of aliens that are issued visas: immigrants and nonimmigrants. Humanitarian admissions, such as asylees, refugees, parolees and other aliens granted relief from deportation, are handled separately under the Immigration and Nationality Act (INA). Persons granted asylum or refugee status are ultimately eligible to become legal permanent residents (LPRs). Illegal aliens or unauthorized aliens include those noncitizens who entered the United States without an official inspection at a port of entry, entered with fraudulent documents, or who violated the terms of their visas after entering the United States. Aliens who wish to come to live permanently in the United States must meet a set of criteria specified in the INA. They must qualify as a spouse or minor child of a U.S. citizen; a parent, adult child, or sibling of an adult U.S. citizen; a spouse or minor child of a legal permanent resident; an employee that a U.S. employer has gotten approval from the Department of Labor to hire; a person of extraordinary or exceptional ability in specified areas; a refugee or asylee determined to be fleeing persecution; winner of a visa in the diversity lottery; or a person having met other specialized provisions of law. Petitions for immigrant (i.e., LPR) status are first filed with USCIS by the sponsoring relative or employer in the United States. If the prospective immigrant is already residing in the United States, the USCIS handles the entire process, which is called "adjustment of status." If the prospective LPR does not have legal residence in the United States, the petition is forwarded to Consular Affairs in their home country after USCIS has reviewed it. The Consular Affairs officer (when the alien is coming from abroad) and USCIS adjudicator (when the alien is adjusting status in the United States) must be satisfied that the alien is entitled to the immigrant status. Foreign nationals who seek to come to the United States temporarily rather than to live permanently are known as nonimmigrants. These aliens are admitted to the United States for a temporary period of time and for an expressed reason. There are 24 major nonimmigrant visa categories, and over 70 specific types of nonimmigrant visas are issued currently. Most of these nonimmigrant visa categories are defined in §101(a)(15) of the INA. These visa categories are commonly referred to by the letter and numeral that denotes their subparagraph in §101(a)(15), e.g., B-2 tourists, F-1 foreign students, H-1B temporary professional workers, or J-1 cultural exchange participants. Most visitors, however, enter the United States without nonimmigrant visas through the Visa Waiver Program (VWP). This provision of the INA allows the Attorney General to waive the visa documentary requirements for aliens coming as visitors from 38 countries. Since aliens entering through VWP do not have visas, CBP inspectors at the port of entry perform the background checks and admissibility reviews. The documentary requirements for visas are stated in §§221-222 of the INA, with some discretion for further specifications or exceptions by regulation. Generally, the application requirements are more extensive for aliens who wish to permanently live in the United States than those coming for visits. The amount of paperwork required and the length of adjudication process to obtain a visa to come to the United States are analogous to that of the Internal Revenue Service's (IRS's) tax forms and review procedures. Just as persons with uncomplicated earnings and expenses may file an IRS "short form" while those whose financial circumstances are more complex may file a series of IRS forms, so too an alien whose situation is straightforward and whose reason for seeking a visa is easily documented generally has fewer forms and procedural hurdles than an alien whose circumstances are more complex. The visa application files must be stored in an electronic database that is available to immigration adjudicators and immigration officers in DHS. There are over 70 U.S. Citizenship and Immigration Services (USCIS) forms as well as DOS forms that pertain to the visa issuance process. The visa issuance procedures delineated in the statute require the petitioner to submit his or her photograph, as well as full name (and any other name used or by which he or she has been known), age, gender, and the date and place of birth. Depending on the visa category, certain documents must be certified by the proper government authorities (e.g., birth certificates and marriage licenses). All prospective LPRs must submit to physical and mental examinations, and prospective nonimmigrants also may be required to have physical and mental examinations. The statutory provision that gives the consular officer the authority to disqualify a visa applicant is broad and straightforward: No visa or other documentation shall be issued to an alien if (1) it appears to the consular officer, from statements in the application, or in the papers submitted therewith, that such alien is ineligible to receive a visa or such other documentation under section 212 [8 USC §1182], or any other provision of law, (2) the application fails to comply with the provisions of this Act, or the regulations issued there under, or (3) the consular officer knows or has reason to believe that such alien is ineligible to receive a visa or such other documentation under section 212 [8 USC §1182], or any other provision of law.... These determinations are based on the eligibility criteria of the various and numerous visa categories. The shorthand reference for these disqualifications is §221(g), which is the subsection of the INA that provides the authority. A §221(g) disqualification is generally the most common reason an LPR visa is denied. DOS disqualified 290,369 LPR visas in FY2013 and 240,876 LPR visas in FY2014. In terms of nonimmigrant visas, DOS disqualified 775,201 visas in FY2013 and 689,379 visas in FY2014. Overwhelmingly, the most common reason that DOS denies nonimmigrant visas is the "failure to establish entitlement to nonimmigrant status." Specifically, §214(b) of the INA generally presumes that all aliens seeking admission to the United States are coming to live permanently; as a result, most aliens seeking a nonimmigrant visa must demonstrate that they are not coming to reside permanently.