Most people can apply for a green card only after a visa petition filed by a relative, fiancé, or employer has been approved and the person has waited until an immigrant visa number is available. Exceptions exist, however. For one, immediate relatives, such as the spouse, parents, and minor unmarried children of U.S. citizens, don't need to wait for visa numbers and can apply for green cards either simultaneously with submitting the visa petition or after the petition has been approved, depending on their circumstances. Refugees and asylees are another exception: They don't need visa petitions at all, but can apply for a green card after one year of gaining their status.
If you're not sure what a visa petition is or whether you needed one, see the Nolo article The Visa Petition: First Step for Family and Employment Green Cards. If your visa number has become available, you should receive notification from the U.S. government or can check the Priority Date from your visa petition approval notice against the current State Department Visa Bulletin.
The next step will be to figure out where to apply for your green card. While most green card applications must be made at U.S. embassies and consulates abroad, many people would prefer to file paperwork while inside the United States, with the agency known as U.S. Citizenship and Immigration Services (USCIS), through a process called adjustment of status. That's often because they are either already living in the United States or they want to join their family or start their new job there as soon as possible. Unfortunately, the choice is not always the immigrant's to make.
Only certain categories of applicants are allowed to file green card applications at a USCIS office. This right is usually limited to people who entered the United States legally and didn't stay beyond the date on their Form I-94.
One important exception is immigrants who are the immediate relative of a U.S. citizen, such as a husband or wife, and applying on that basis. If they entered legally, or on a visa waiver, and even if they stayed past the date when they were expected to leave, they can normally still apply in the United States.
For other applicants, particularly those who entered the United States illegally or overstayed a visa, filing in the United States may cause their deportation. Anyone considering applying in the United States should consult a Nolo book specific to their situation or hire an experienced immigration attorney. For listings of attorneys in your area, complete with personal profiles, see the Nolo Lawyer Directory.
To get a green card while inside the United States, you need to apply for what is called "adjustment of status." Any local USCIS office can give you the packet of forms you need. Or you can call their forms line at 800-870-3676 and ask for an adjustment of status packet, or download the individual forms at www.uscis.gov. Some of these forms require paying fees to submit them.
In addition, you'll have to provide photos and various documents, such as a copy of your visa petition approval or asylum approval, a letter from the employer who petitioned you (if you're applying based on employment) saying the job is still open, your birth certificate, copies of certain pages of your passport, and more. It depends on what category you're applying under.
After you've assembled everything (and made a copy for your records), you'll mail it to a USCIS service center (not the kind of USCIS office that you can visit in person). Months later, you'll be called in to have your fingerprints taken and, later still, you'll be called to your local USCIS office for an interview. If everything is in order, you will be approved for a green card at the end of your interview. The actual green card will be sent to you by mail, usually weeks or months later.
If you're living outside the United States, an office called the National Visa Center (NVC) will start corresponding with you (and your petitioner) after your visa petition has been approved and your Priority Date is current. The NVC will take care of transferring your case to a U.S. embassy or consulate in the country where you live.
(U.S. embassies and consulates outside your home country will normally refuse to accept your application, unless you can show a compelling reason why you are unable to apply at home, for example, because the United States has no diplomatic relationship with the government of your homeland.)
The consulate will call you in for an interview and give you instructions on getting a medical exam and photos done beforehand. You'll have to prepare various documents to bring to your interview, such as your passport, police certificates, your birth and marriage certificates, and more. It depends on what category you're applying under.
Even with an appointment, you'll still normally have to stand in line. At the interview, a consular officer will review your documents and talk with you. If everything is in order, you'll be approved for an immigrant visa, and your passport will be stamped. You'll need to use that visa within six months to enter the United States and claim your permanent resident status. The actual green card will be sent to you by mail, usually weeks or months later.
This article is an overview of the very complicated application procedures involved in immigrating to the United States. You'll also need to know which forms to file and where, as well as the proper documents to bring to your interview, and this depends on what category you're applying under (fiance, spouse, employee, relative, and so on). Nolo books can provide further help, with detailed instructions specific to the various types of visas and green cards:
U.S. Immigration Made Easy, by Ilona Bray.
Fiancé and Marriage Visas: A Couple's Guide to U.S. Immigration, by Ilona Bray.
How to Get a Green Card, by Ilona Bray