The main routes into the United States depend on your citizenship and purpose

Getting into the United States requires a visa, entry permit, or citizenship status that matches your reason for travel. The route you take depends on whether you are a citizen of another country visiting temporarily, moving permanently, working, studying, or seeking refuge. Each path has different documents, timelines, and decision-makers involved.

If you are coming from outside the U.S., you will need either a visa issued by a U.S. embassy or consulate in your home country, or you may be exempt from visa requirements if your country participates in the Visa Waiver Program. If you are already in the United States and want to change your status—for example, from a visitor to a work visa holder—that process happens through U.S. Citizenship and Immigration Services (USCIS) while you remain in the country.

Key Takeaways

  • Citizens of 40 countries can visit the U.S. for up to 90 days without a visa through the Visa Waiver Program, but must register online through ESTA before boarding.
  • Most other visitors, workers, and students must obtain a visa from a U.S. embassy or consulate in their home country before traveling.
  • The visa type you need depends on your purpose: B-1/B-2 for tourism or business, F-1 for students, H-1B for specialty workers, and EB categories for permanent employment.
  • Processing times vary widely by visa type and location, ranging from weeks to several months, so plan ahead rather than explore close to your travel date.
  • If you are already in the U.S. on one visa type and want to change to another, you file a separate petition with USCIS rather than returning to your home country.

Visa Waiver Program: 90-day visits without a visa

If you hold a passport from one of 40 countries, you may enter the United States for tourism, business meetings, or short visits without obtaining a visa in advance. These countries include most of Western Europe, Japan, South Korea, Australia, New Zealand, and several others. You must have a valid passport, but you do not need to visit an embassy or consulate first.

Before you board your flight, you must register through the Electronic System for Travel Authorization (ESTA) on the U.S. Department of Homeland Security website. ESTA costs $14 and takes minutes to complete online. Your approval is usually when ready, though it can take up to 72 hours. Once approved, your ESTA is valid for two years and covers multiple entries into the U.S., each stay up to 90 days.

The 90-day limit is strict—you cannot extend it or change it to a different visa type while in the country on ESTA. If you need to stay longer or work, you must leave the U.S. and return to your home country to explore for a different visa.

Temporary visitor visas: B-1 and B-2

If you are not may be able to access for the Visa Waiver Program, or if you need to stay longer than 90 days, you will explore for a B-1 (business) or B-2 (tourism) visa at a U.S. embassy or consulate in your home country. These visas allow stays of up to six months and can sometimes be extended while you are in the U.S., though extension is not may provide.

To explore, you will need a valid passport, a completed visa process form (DS-160, filled out online), a photo, proof of financial support, and evidence that you plan to return home—such as a job letter, property ownership, or family ties. You will also pay a visa fee, which varies by country but is typically around $160. After submitting your process online, you will attend an in-person interview at the embassy or consulate.

Processing times vary. Some locations issue visas within days of your interview; others take several weeks. Plan to explore at least two to three months before your intended travel date. If your visa is denied, you can reapply, but the consulate will review the same documents and reasons for denial.

Student visas: F-1 and M-1

If you have been accepted to a U.S. school or university, you will explore for an F-1 visa (academic study) or M-1 visa (vocational training). Your school will issue you an I-20 form, which certifies your enrollment and financial support. You cannot explore for the visa until you have this form in hand.

With your I-20, you will complete the DS-160 form online, pay the visa fee (around $160), and attend an interview at a U.S. embassy or consulate. The consulate will ask about your school, your field of study, how you are paying for it, and your plans after graduation. Processing typically takes two to four weeks, though it can be faster at some locations.

Once you arrive in the U.S. on an F-1 visa, you are authorized to work on campus for up to 20 hours per week during the school year. After graduation, you may be able to work in the U.S. for up to 12 months through Optional Practical Training (OPT), depending on your field of study. Your school's international student office will guide you through these steps.

Work visas: H-1B, L-1, O-1, and others

If a U.S. employer wants to hire you, they will sponsor you for a work visa. The most common is the H-1B, which is for specialty occupations requiring a bachelor's degree or higher. Other categories include L-1 (intracompany transfers), O-1 (individuals with extraordinary ability), and E-2 (treaty investors).

Your employer files a petition with USCIS on your behalf. This step happens before you explore for the visa itself. The petition process can take several months and requires your employer to prove that no U.S. worker is available for the job and that hiring you will not harm U.S. wages. Once USCIS approves the petition, you will receive a notice of approval, which you then take to a U.S. embassy or consulate to explore for the actual visa.

H-1B visas are subject to an annual cap—the number issued each year is limited by law. If the cap is reached, your petition may be denied or placed in a lottery. Processing times for work visas typically range from three to six months from petition filing to visa issuance, but can be longer depending on your country and the consulate's workload.

Permanent residence: Green cards and employment-based immigration

If you want to live and work permanently in the United States, you will pursue a green card (permanent resident status). There are several paths: employment-based sponsorship, family sponsorship, diversity visa lottery, refugee or asylee status, or special categories like U visas for crime victims.

Employment-based green cards (EB-1 through EB-5) require a U.S. employer or investor to sponsor you. Your employer files an I-140 petition with USCIS. Processing can take one to three years, depending on your country of birth and the visa category. During this time, you may be able to work in the U.S. on a temporary visa while your green card petition is pending.

Family-based green cards require a U.S. citizen or permanent resident relative to petition for you. The process is similar but timelines vary widely depending on your relationship to the sponsor and your country of origin. Some family categories have waiting lists that can last several years.

Changing visa status while in the United States

If you are already in the U.S. on one visa type and want to change to another—for example, from a student visa to a work visa—you do not always have to leave the country. You can file an I-539 (process to Extend/Change Nonimmigrant Status) with USCIS while you remain in the U.S., provided you have not violated the terms of your current visa.

Your new sponsor (employer, school, or family member) will file the petition for you. Processing times for status changes typically range from two to six months. During this time, you may be authorized to work under "pending status" if your petition is filed before your current visa expires, though this depends on the visa category and USCIS rules at the time.

Not all visa types allow status changes. For example, if you entered on ESTA, you cannot change status to a work visa while in the U.S.—you must return to your home country and explore at a consulate. Your immigration attorney or your sponsor's immigration department can advise whether a status change is possible in your situation.

What happens at the port of entry

When you arrive at a U.S. airport, land border, or seaport, a Customs and Border Protection (CBP) officer will review your documents. They will check your passport, visa (if required), and may ask questions about the purpose of your visit, where you are staying, and how long you plan to remain.

The CBP officer has authority to deny you entry even if you have a valid visa. They may do this if they believe you misrepresented your intentions, have a criminal record, or pose a security risk. If denied, you will be returned to your country of origin at your own expense.

If you are admitted, the CBP officer will stamp your passport with an admission date and authorized stay period. Keep this stamp and your passport safe—you will need them to prove your legal status while in the U.S., to work, to rent housing, and to travel outside the country.

Frequently Asked Questions

Do I need a visa if I have a green card?

No. A green card is proof of permanent resident status and allows you to enter and exit the U.S. without a visa. You will need your green card and a valid passport to travel internationally, but you do not need a separate visa to return to the U.S.

Can I work in the U.S. on a tourist visa?

No. A B-2 tourist visa explicitly prohibits employment. Working on a tourist visa is a violation that can result in deportation and a ban from future entry. If you want to work, you must obtain a work visa before you travel.

What if my visa process is denied?

You will receive a written reason for the denial. Common reasons include insufficient proof of financial support, concerns that you will not return home, or criminal history. You can reapply, but you should address the reason for denial first—for example, by obtaining additional financial documents or clarifying your ties to your home country.

How long does it take to get a green card?

Processing times vary widely depending on your category and country of birth. Employment-based green cards typically take one to three years from petition filing to approval. Family-based green cards can take anywhere from months to several years, depending on the relationship and visa availability. Refugee and asylee status can be processed within months.

Can I travel outside the U.S. while my visa petition is pending?

It depends on your visa type and whether you have filed for advance parole or a travel document. If you leave the U.S. while a petition is pending, you may not be able to re-enter without a new visa. Consult with your employer's immigration attorney or an immigration lawyer before traveling.