If you are a citizen, you can sponsor your wife, husband, children of any age,
even if married, parents, and brothers and sisters.
If you have a green card, you can sponsor your wife, husband and/or children of any age as long as they are not married.
If you are a child over age 21 or brother or sister of a U.S. citizen, and you live in the United States, you must be in status to apply for a green card without leaving.
In other words, your visa or stay must not be expired.
If you are wife, husband, child under 21 or parent of a citizen, you only need to prove that you entered the United States legally such as with visa or parole, even if your status has expired. The U.S. only looks at how you entered to decide your case, not your current status.
If the sponsor is not a citizen but has a green card, the wife, husband or children must be in status. Their visa or stay must not be expired.
If you meet these requirements, then you can file for your adjustment of status to become a permanent resident. You will need to file the I-130 relative petition with the application or proof that it was already filed. You will need to file other proof of eligibility including your passport and visa, proof of relationship with the family member such as marriage certificate, birth certificate, etc. You will also need a medical which is form made by a doctor approved by USCIS who knows what is required for the green card and how to complete form.
Another requirement for a green card application is an affidavit of support (I-864) in which the petitioner must show they have enough income to support the immigrant. This information is on immigration website where you can find the form I-864. He/she must provide a copy of the latest tax return, a job letter and the latest bank statement to prove income. The minimum income requirement depends on the size of the family and how many immigrants are being sponsored. For one person sponsoring one immigrant totaling two people, the minimum is $20,575. The minimum goes up about $5000 for each person in the family or the immigrant's family.
If the petitioner does not have enough income or doesn't file tax returns, she/he needs a joint sponsor, someone else who either has citizenship or green card who has minimum income requirements.
The immigration law that required immigrants to have legal status to apply as discussed above was in effect since May 1, 2001. If an immigrant in the United States was a beneficiary of a petition or labor certification filed by April 30, 2001, they can apply for a green card even if they entered the United States illegally or without inspection. They must prove that they were physically inside the United States on December 2000. If the immigrant had a petition by a husband or wife filed before April 30, 2001, he must also prove that marriage was real and not just a paper or contract marriage for green card. This is required even if the immigrant is applying for a different reason.
If an immigrant was the beneficiary of a petition filed before January 14, 1998, he does not need to prove presence in the United States at any time or that the marriage on which the petition is based was real.
Citizens and permanent residents can sponsor their family members who are outside the United States. If the immigrant has a wife and children, they can all immigrate at the same time. The exception is if a citizen sponsors their parents, the children cannot come with them.
To do this, you must file an I-130 petition just as you would when the immigrant is already in the United States. When it is approved it goes to an office called the National Visa Center which is part of the State Department. When the National Visa Center has it, you must fill out an online form called the DS-260 for each immigrating family member. You must do an affidavit of support as described above with the required documents. You must also submit what they call civil documents for all people immigrating: Birth certificates, passports, marriage certificates, if any, police certificates to certify they have no criminal record. Once complete, the case is scheduled at the embassy where the immigrants live for an appointment for immigrant visas.
If an immigrant is subject of an I-130 petition and in the United States but meets none of the eligibility requirements to apply for a green card in the United States, the only way he can get a green card is if he leaves the United States. If you entered the United States illegally or your visa has expired, etc. you would have to follow the procedure through the embassy as described above. The problem is that if you were living illegally in the United States for one year, you will be barred from returning legally for ten years. However, you don't need to wait that long if you do a waiver. That means that if you have a husband, wife or parent who has a green card or U.S. citizenship and they would suffer extreme hardship without you, the government will forgive you and you can return to the United States immediately with your immigrant visa. To do this, you need to follow the same procedure to go through the embassy. You can only file the waiver after the petition is approved and you have paid the fees to the National Visa Center.