Nonimmigrants, who are admitted into the United States temporarily, are not admitted through this preference system. There are five preference categories for employment-based LPRs and each has its own eligibility requirements and numerical limitations, and at times different application processes. The Departments of State (DOS) and Homeland Security (DHS) each play key roles in administering the law and policies on the admission of migrants. Citizenship and Immigrant Services (USCIS) in DHS must first approve immigrant petitions. The same analyses of approved pending employment-based petitions are performed on two different sets of data: approved pending petitions with the DOS National Visa Center; and approved pending petitions with USCIS, known by the petition number as the I-485 Inventory. In addition to preference category numerical limitations, the INA specifies that each year countries are held to a numerical limit of 7% of the worldwide level of U.S. immigrant admissions, known as per-country limits or country caps. Most foreign nationals who become LPRs were already living in the United States. Visas for 3 rd preference "professional, skilled, and unskilled workers" visas had a March 15, 2016, priority date, but China, India, and the Philippines had longer waits. There were 100,747 approved petitions for employment-based LPR visas pending with the National Visa Center as of November 1, 2015. In addition, there were 17,662 approved 5 th preference "immigrant investor" visas pending. There were also 3,474 approved 1 st preference "extraordinary" visas and 379 4 th preference "special immigrant" visas pending. Figure 5 shows that India's approved visas pending at the National Visa Center are mostly in the 3 rd preference "professional, skilled, and unskilled worker" category (21,590); however, India has a noteworthy portion of approved pending visas in the 2 nd preference category for those with advanced degrees (7,646). Adjustment of Status: Approved I-485 Petitions Pending

Approved visa petitions that are pending at the NVC are not the only source of pending employment-based LPR petitions. There are 30,457 approved I-485 petitions pending in the 1 st preference category and 37,971 approved I-485 petitions pending in the 3 rd preference category. The data in Figure 9 , along with the previous analyses, suggest that the majority of Indians are waiting to adjust status in the United States, while the majority of Filipinos are waiting to immigrate from abroad. Even as the number of unemployed individuals outnumbers the number of open positions, some employers assert that they continue to need the "best and the brightest" workers, regardless of their country of birth, to remain competitive in a worldwide market and to keep their firms in the United States. While support for the option of increasing employment-based immigration may be dampened by economic conditions, proponents argue it is an essential ingredient for economic growth. Those opposing increases in employment-based LPRs in particular assert that there is no compelling evidence of labor shortages and cite the rate of unemployment across various occupations and labor markets. Changing Per-country Limits42

With this economic and political backdrop, the option of lifting the per-country caps on employment-based LPRs has gained attention. Some observers contend that the elimination of the per-country caps would increase the flow of high-skilled immigrants without increasing the total annual admission of employment-based LPRs. The presumption is that many high-skilled people (proponents cite those from India and China, in particular) would then move closer to the head of the line to become LPRs. Legislative options that have been suggested include the following:
a targeted lifting of the country caps on the top two preference categories of priority workers and those who are deemed exceptional, extraordinary, or outstanding individuals; a categorical lifting of the country caps on all employment-based preference categories, up to the 140,000 worldwide ceiling on employment-based LPRs; or a complete lifting of the country caps on all employment-based preference categories as well as excluding employment-based LPRs from the calculation of the family-based and worldwide per-country ceilings. Proponents of per-country ceilings maintain that the statutory per-country ceilings restrain the dominance of high-demand countries and preserve the diversity of the immigrant flows.
The Immigration and Nationality Act (INA) specifies a complex set of numerical limits and preference categories for admitting lawful permanent residents (LPRs) that include economic priorities among the criteria for admission. Employment-based immigrants are admitted into the United States through one of the five available employment-based preference categories. Each preference category has its own eligibility criteria and numerical limits, and at times different application processes. The INA allocates 140,000 visas annually for employment-based LPRs, which amount to roughly 14% of the total 1.0 million LPRs in FY2014. The INA further specifies that each year, countries are held to a numerical limit of 7% of the worldwide level of LPR admissions, known as per-country limits or country caps.
Some employers assert that they continue to need the "best and the brightest" workers, regardless of their country of birth, to remain competitive in a worldwide market and to keep their firms in the United States. While support for the option of increasing employment-based immigration may be dampened by economic conditions, proponents argue it is an essential ingredient for economic growth. Those opposing increases in employment-based LPRs assert that there is no compelling evidence of labor shortages and cite the rate of unemployment across various occupations and labor markets.
With this economic and political backdrop, the option of lifting the per-country caps on employment-based LPRs has become increasingly popular. Some argue that the elimination of the per-country caps would increase the flow of high-skilled immigrants without increasing the total annual admission of employment-based LPRs. The presumption is that many high-skilled people (proponents cite those from India and China, in particular) would then move closer to the head of the line to become LPRs.
To explore this policy option, analyses of approved pending employment-based petitions are performed on two different sets of data: approved pending petitions with the Department of State (DOS) National Visa Center (NVC), and approved pending petitions with U.S. Citizenship and Immigrant Services (USCIS). Because DOS and USCIS play different roles in the visa application process, their datasets represent different populations. DOS's data from the NVC contains individuals who apply for a visa while residing outside of the United States. They are considered new arrivals once they are issued a visa and enter the United States. USCIS's data contains individuals who are already residing in the United States and are applying to change their immigration status from a temporary status to a permanent LPR visa. This process is referred to as an adjustment of status.
As of November 2015, there were 100,747 approved employment-based LPR petitions pending at the National Visa Center. The 3rd preference category of "professional, skilled, and unskilled" workers had the highest number of pending approved petitions (67,792). The 5th preference category of "immigrant investors" had 17,662 approved petitions pending and the 2nd preference category of "advanced degree" workers had 11,400 approved petitions pending. There were also 3,747 approved petitions pending for the 1st preference category of "extraordinary" workers and 379 for the 4th preference category for "special immigrants."
In terms of the USCIS data, there were a total of 117,731 approved I-485 petitions pending as of April 2016, and most were for the 2nd preference "advanced degree" workers (46,765). There were 37,971 approved I-485 petitions pending in the 3rd preference "professional, skilled, and unskilled" category and 30,457 pending in the 1st preference "extraordinary" category. In addition, there were 1,409 5th preference "immigrant investor" and 1,129 4th preference "special immigrant" approved I-485 petitions pending.
The top four countries in the National Visa Center data set were (in descending rank order) India, the Philippines, China, and South Korea. The top four countries in the USCIS data sets were (in descending rank order) India, China, the Philippines, and Mexico. The data indicates that more Indians and Mexicans are waiting to adjust status in the United States, while more Filipinos and Chinese are waiting to immigrate from abroad.
Some argue that the per-country ceilings are arbitrary and observe that employability has nothing to do with country of birth. Others maintain that the statutory per-country ceilings restrain the dominance of high-demand countries and preserve the diversity of immigrant flows.