Citizens of foreign countries who wish to obtain permanent resident status in the U.S. generally must obtain immigrant visas at the appropriate Consulate or U.S. Embassy. Unlike nonimmigrant tourist, student, and specialty worker visas, which allow someone to remain in the United States for a limited period of time, an immigrant visa permits the person who receives it to live indefinitely in the United States and to seek employment.

There are 3 types of immigrant visa categories:

• Family based immigration
  
  
• Employment based immigration
  
  
• Diversity Visa - Lottery
  Persons born in certain countries (such as India, China, Mexico etc.) are not eligible to participate in green card lottery as already so many people from those countries apply for visas in other categories.
  
  

In consular processing, the interview for an immigrant visa takes place at a U.S. Embassy or Consulate that has the jurisdiction over the beneficiary.

When your petition is approved, USCIS sends it to the National Visa Center (NVC).

There is a delay between when you get the notice of approval from USCIS and when NVC receives the petition. After NVC receives the petition, it will create a case record and assign a case number, usually within 24 hours of being received from the USCIS. Case number is used to track the case throughout its duration at the NVC. You should wait at least wait 3 weeks after you get your Notice of Approval before calling NVC if you have not heard from NVC by that time.

If the case is not current, NVC will send you a letter informing you that they have your file at NVC and they will hold it until your case becomes current.
Sample letter

NVC retains the case until it is ready for adjudication by a consular officer abroad. Petitions may remain at NVC for several months or for many years depending on the visa category and country of birth of the visa applicant. When an applicant's case is about to become current (a visa number is likely to be available within the year), NVC will start and complete its processing before the petition is forwarded to the appropriate U.S. Embassy or Consulate overseas. Each petition is reviewed by at least two people before being sent to the consulate, assuring quality control. If an applicant is adjusting status in the U.S., the case will be forwarded to the appropriate USCIS office upon request by that office.

Do not take any action described below without notification from the National Visa Center (NVC). Doing so could result in a delay in processing. Forms received before official notifications will be discarded.

When an applicant's priority date is close to becoming current,

• NVC will send an Affidavit of Support (AOS) processing fee bill to the petitioner and a Form DS-3032 Choice and Address and Agent to the applicant. Electronic Processing candidates will fill Form DS-261 online instead.
  
  NVC fee payment details
  
  
• Once the I-864 processing fee is paid, NVC will send the I-864 forms and instructions to the petitioner. Instead of NVC sending you the actual forms, you may be asked to download them. In that case, download them and complete them.
  
  The completed I-864 form and supporting documents should be sent back to NVC. Do not send it to the consulate. Make sure to include the bar code sheet for the applicant's case.
  
  
• Once NVC receives the form DS-3032 from the applicant (or DS-261 for Electronic Processing candidates), NVC will mail the Immigrant Visa (IV) fee bill to the agent of choice.
  
  NVC fee payment details
  
  
• Once the IV fee bill is paid, NVC will send the Instructions Package for Immigrant Visa Applicants (formerly known as Packet 3) to the agent of choice.
  
  The exact contents of the Instruction Packet will depend on where the applicant will be interviewed for an immigrant visa. Applicant should send the required documents as per the instructions.
  
  
• Once NVC (or the Embassy/Consulate in some cases) receives all required documents, NVC (or the Embassy/Consulate in case of standard review posts or DCF cases) will schedule an interview within 60 to 90 days, if the priority date is current. They will send an "Appointment Package for Immigrant Visa Applicants" (Formerly known as Packet 4) to the applicant.
  
  
• Applicant and all accompanying family members (spouse and children) need to go for an immigrant visa medical examination.
  
  
• Applicant and all accompanying family members (spouse and children) must visit the Consulate on the appointment day for an immigrant visa interview.

If the beneficiary is already in the U.S., the petitioner can designate either consular processing or adjustment of status while filing I-130 (Family based) or I-140 (Employment based) petition. When the petition is approved by USCIS, it will be sent to NVC for further processing.

If you live in the U.S., you may be eligible for an adjustment of status as a permanent resident. When your case becomes current, NVC will send you a letter stating that you may be eligible for adjustment of status and asking whether you will adjust or apply at a U.S. consular section abroad. If you write back to NVC that you will adjust status, they will note it on your case record and retain the file until a USCIS office requests it to process your adjustment application. If NVC does not get a reply to their letter after 30 days, they will begin processing your case as if you have chosen to process at a consular office abroad. NVC is not involved in adjustment of status and it should be done with USCIS.

If the petitioner indicated that the beneficiary will do adjustment of status in the U.S., and later changes the mind and would like to do consular processing, petitioner must file Form I-824 to have USCIS transfer the file to NVC for further processing. NVC will start the process as described above. Filing of I-824 can delay the processing considerably. In some cases, it may be possible to proceed on the basis of an "attorney certified copy" of the petition.