One method to obtaining lawful permanent residency is through a relative who is either a citizen of the US or a lawful permanent resident.

U.S. Citizen May Petition for:

• Spouse
• Children (unmarried and under 21)
• Sons and daughters (married and/or 21 or over)
• Parents, if you are 21 or over
• Siblings, if you are 21 or over

• The spouse of a permanent resident
• The child (unmarried and under 21 years old) of permanent resident
• The unmarried son or daughter (21 years or older) of a permanent resident

Application Process: Green Card

To petition for a family member to receive a green card, you must submit Form I-130, Petition for Alien Relative and  the following documentation with your Form I-130:

• Proof of your U.S. citizenship;
• Evidence of the qualifying relationship (birth certificate, marriage certificate, divorce decree, etc.) If the child was born out of wedlock, you must show that bona-fide relationship between you and the child existed, financial support, and continuous interest in the child's welfare;
  
• Proof of any legal name change for you or the beneficiary;
• Form G325A;
• A passport style photo of petitioner and beneficiary;
• An appropriate filing fee; spell out "U.S. Department of Homeland Security" on a check.
  

       * Spouses of deceased U.S. permanent residents may also be eligible to become permanent residents. 

An approved petition DOES NOT grant any benefit, it simply creates a place in line for visa processing.

• Spouses of U.S. citizens
• Children (unmarried and under 21) of U.S. citizens
• Parents of U.S. citizens (The petitioning citizen must be 21 or older.)

There are four preference categories for limited family-based immigration:

1. First Preference: Unmarried children over the age of 21 of US citizens.
2. Second Preference: 2A—Spouses of lawful permanent residents, their unmarried children under the age of 21,
                           and 2B—Unmarried sons and daughters of permanent residents who are 21 and older.
3. Third Preference: Married children of US citizens.
4. Fourth Preference: Siblings of adult US citizens.

The T nonimmigrant status  was created to provide immigration protection to victims of a severe form of trafficking in persons. The U nonimmigrant status was created for victims of crimes who have suffered mental or physical abuse because of the crime and who are willing to assist law enforcement and government officials in the investigation of the criminal activity.

The eligibility requirements

 USCIS may grant permanent residency status to spouses, children, and parents to U-Visa holders if:

Procedure for applying for lawful permanent residence

The U-1 status holder must file an immigrant petition on the new Form I-929, Petition for Qualifying Family Member of a U-1 Nonimmigrant. If the I-929 is approved on their behalf, qualifying family members in the U.S. may file Form I-485, Application to Register Permanent Residence or Adjust Status. Qualifying family members outside the U.S. may visit a U.S. embassy or consulate to obtain their immigrant visas.

You may also be eligible to get a green card if you: 

• Are a battered child or spouse of a U.S. citizen
• Entered the United States with a K visa as the fiancé(e) or spouse of a U.S. citizen or an accompanying child
• Obtained V nonimmigrant status
• Are a widow(er) of a U.S. citizen 
• Are born to a foreign diplomat in the United States