When applying for a green card, immigrants have a number of different options to choose from. The method by which immigrants can try to obtain the legal right to live and work within the United States differs according to circumstances; for example, an immigrant already legally living in the US who wants to become a permanent resident can petition to get an adjustment to their status, while those outside the country may need to use consular processing.

Consular processing can be applied for by an immigrant who is not currently residing in the United States but has an immigrant visa number. Green cards are granted by the US Department of State, which works closely with US Citizenship and Immigration Services when processing such requests.

The first step in applying for a green card via the consular process is to work out the basis for the immigration claim, with applicants needing to fit into at least one INA immigrant category to be eligible. One of the most common methods is for an employer or an immediate relative to file the petition, although there are other categories such as humanitarian programs.

After the petition has been filed, applicants will need to wait for a decision to be made. The result will be sent by mail; if accepted, the National Visa Center will receive the petition and eventually an immigrant visa number will be assigned. A visa packet will then be issued, which needs to be shown unopened upon entering the US. A green card will be issued within 45 days of arrival in the US.