How U.S. Immigration Works: One Map, Every Door In
U.S. immigration looks confusing because people talk about it as if it were one line, one form, or one decision. It is none of those. It is a map with separate roads — some temporary, some permanent, most run by an employer, a few you can travel on your own — and most mistakes come from taking the wrong road, or expecting one road to do another road's job. This page is the map. The law underneath all of it is the Immigration and Nationality Act, the INA.
Start with the basic split. A nonimmigrant comes for a specific purpose for a limited time — to work in a particular job, to study, to visit. An immigrant comes to live here permanently, as a lawful permanent resident: a green card holder, free to live and work anywhere in the United States. Almost every category in the system sits on one side of that split or the other, and the rules, the forms, and the waits are different on each side.
Three words people use as if they were the same are not the same. A petition is a request, usually by an employer or a relative, asking the government to classify a person in a category. A visa is a travel document placed in a passport by a U.S. consulate abroad; it lets the holder travel to the United States and ask to enter, but it does not guarantee entry, and it is not itself the permission to stay. The officer at the port of entry, from Customs and Border Protection, decides admission — and the status granted on admission, not the visa in the passport, governs how long the person may stay and what the person may do while here.
The work roads on the temporary side are classifications, each built for a different situation. The H-1B is for a specialty occupation — a job that requires a bachelor's degree or higher in a specific field, or its equivalent. The L-1 moves an employee who has worked abroad for a related company into its U.S. operation, as a manager or executive, or for the employee's specialized knowledge. The O-1 is for a person of extraordinary ability, or, in the arts and in film and television, extraordinary achievement, coming to do a specific job or engagement. TN is for Canadian and Mexican citizens in professions listed in the United States-Mexico-Canada Agreement. And the E classifications are for nationals of treaty countries — treaty traders, treaty investors, and certain of their employees. There are other temporary classifications, for visitors, students, and more; these are the work roads.
Notice what the temporary classifications share. Most are tied to a specific employer, job, or engagement: the approval is for that work, not for working in general, and changing jobs usually means a new petition or a new application first. Each has its own time limits and its own rules on extension. Holding a temporary status does not by itself make anyone a permanent resident — although some classifications, notably H-1B and L-1, tolerate the pursuit of permanent residence in a way others do not, and the permanent case is often filed while the temporary one is running.
An employer-sponsored temporary case usually runs in a fixed order. Where the category requires it — H-1B is the standard example — the employer first files a Labor Condition Application with the Department of Labor, attesting to the wage it will pay and the working conditions it will maintain. For a cap-subject H-1B, selection in the annual registration comes before a petition can be filed at all. The employer then files the petition with U.S. Citizenship and Immigration Services, USCIS, which decides whether the job and the person fit the classification. If the worker is abroad, the worker next applies at a consulate for the visa; if the worker is already here in a lawful status, the petition can instead ask USCIS to change or extend that status. No step substitutes for another: a certified Labor Condition Application is not a petition approval, and a petition approval is not a visa.
On the permanent side, employment-based immigration runs through five preference categories, EB-1 through EB-5. EB-1 is for priority workers: people of extraordinary ability, outstanding professors and researchers, and certain multinational managers and executives. EB-2 is for professionals holding an advanced degree, people of exceptional ability, and national interest waiver cases. EB-3 is for skilled workers, professionals, and other workers. EB-4 is for special immigrants defined by statute. EB-5 is for investors whose investment creates jobs. The categories are preferences in a real sense: each gets a share of a limited annual supply, and when the demand in a category runs past its share, a line forms.
Here is the supply. The worldwide employment-based level is at least 140,000 immigrant visas a year — that figure, in the statute, is a floor, not the final number. The count includes the worker's spouse and children, so the number of workers who actually receive green cards through employment is smaller than the headline number. Within the total, EB-1, EB-2 and EB-3 each receive 28.6 percent, plus any numbers the categories ahead of them did not use; EB-4 and EB-5 each receive 7.1 percent. Numbers also move between the two big systems: unused family-sponsored numbers from one year are added to the employment-based level for the next, which is how a given year's employment total can land well above 140,000. What movement of numbers cannot do is create numbers Congress never authorized.
On top of the category limits sits a per-country limit: people chargeable to any one country may receive no more than 7 percent of the combined family-sponsored and employment-based preference numbers in a year. Chargeability normally follows country of birth, not citizenship and not where the person lives now. That single rule is why two workers in the same category, with the same kind of case, can face completely different waits depending on where each was born. I have written separately about the per-country caps and the bills that would have removed them.
The employer-sponsored permanent case has its own chain, and it is not the temporary chain. For most EB-2 and EB-3 cases, the first step is permanent labor certification — PERM — from the Department of Labor: the employer tests the labor market, recruits as the rules require, and shows that no qualified, willing U.S. worker is available for the job. That filing is not the Labor Condition Application used for H-1B; the similar names hide different work — one attests to a wage and working conditions, the other certifies the result of a labor-market test. Next, the employer files the immigrant petition, Form I-140, with USCIS, which places the worker in a preference category. Where labor certification was required, the worker's priority date — the worker's place in line — is the date the labor certification application was filed with the Labor Department. Some permanent cases skip labor certification entirely: EB-1 cases, national interest waivers, and EB-4 and EB-5 among them. And in two of them, EB-1 extraordinary ability and the national interest waiver, the worker can petition without an employer sponsor at all.
The last step depends on where the worker is, and on whether a visa number is available. A worker in the United States in a lawful status applies to USCIS to adjust status to permanent resident. A worker abroad applies for an immigrant visa through the Department of State and a consulate, and becomes a permanent resident on admission. Either way, an approved petition is not the green card: a number must actually be available in the category. Availability is published monthly in the Department of State's Visa Bulletin, which carries a Final Action Dates chart, governing when a case can be approved, and a Dates for Filing chart, which sometimes lets an application be filed sooner. When your category and your country reach your priority date, your case can be finished. Until then you wait — and how long that is depends heavily on the country you were born in.
Family immigration is the larger part of the system, and it belongs on this map even though this firm's practice is employment-based. Spouses, unmarried children under 21, and parents of U.S. citizens who are at least 21 are immediate relatives, and there is no annual numerical limit on them at all. Other relatives — adult children and siblings of U.S. citizens, and spouses and unmarried children of permanent residents — come through four family preference categories, under a worldwide level of at least 226,000 a year, calculated from a starting figure of 480,000, minus the immediate relatives and certain other cases from the year before, plus any employment-based numbers that went unused. A separate diversity program makes up to 55,000 immigrant visas a year available by lottery to people from countries with low rates of immigration to the United States, with that number reduced in practice by amounts Congress has directed to other programs. The map also contains a protection side, covering refugee admissions from abroad and asylum for people already in the United States, which is a distinct body of law with its own standards.
If the map still looks complicated, hold on to the agencies, because every case passes through the same hands in the same roles. The Department of Labor handles the labor steps — the wage attestations in temporary cases, the labor-market certification in permanent ones — and enforces the wage and working-condition promises employers make. USCIS decides the petitions and applications filed inside the United States: nonimmigrant classifications, extensions and changes of status, immigrant petitions, and adjustment to permanent residence. The Department of State runs the consulates that issue visas abroad, runs the National Visa Center that prepares immigrant visa cases, and publishes the Visa Bulletin that rations the numbers. Customs and Border Protection decides, at the airport or the border, whether the person standing in front of the officer is admitted, in what status, and until when. A case that seems stalled is usually sitting with one of these four, waiting for the one thing only that agency can do.
Permanent residence is not the end of the map, but it is where the immigration pressure comes off. A permanent resident may work for any employer, or for none, and may generally apply to become a citizen after five years as a resident — three years for a resident who is married to, and living with, a U.S. citizen — if the residence, presence, and other requirements are met. Everything before that point is about picking the right road and running its steps in order. Work out which side of the split you are on, which classification actually fits the job and the person, and which agency holds the next step, and the system stops being a maze. It is a set of limited, rule-bound roads — each of them passable, if you are on the right one.
Tell me what you are working on and I will reply in writing, focusing on the issues involved.
General information, not legal advice. Requirements and processing change; we confirm current rules for your case.