To live with a family in the U.S.
You can acquire permanent residency in the United States if you have family members who live in the US as U.S. citizens or Permanent residents. The family member living in the U.S. files Form I-130 to the USCIS to invite a foreign family member (i.e., beneficiary). If the beneficiary is in the US, I-485 is available depending on the priority date of the case, or if the beneficiary is in Korea (or home country), the beneficiary can change his/her status to a permanent resident (i.e., Green-card holder) through Consular Processing (CP).
According to the family relationship categories below, the process of obtaining permanent residency and the time of the filing I-485 are different.
You can check it though a monthly visa bulletin.
Immediate Relatives (IR)
The spouse of U.S. citizen
The children (unmarried and under 21 years of age) of U.S. citizens
The parents of U.S. citizens at least 21 years old, and
Widows or widowers of U.S. citizens if the U.S. citizen filed a petition before his or her death or if the widow(er) files a petition within 2 years of the citizen’s death.
Unmarried Sons and Daughters of U.S. citizens
Spouses and Children of Permanent Residents (F2A)
Unmarried Sons and Daughters (21 years of age or older) of Permanent Residents (F2B)
Married Sons and Daughters of U.S. citizens
Brothers and Sisters of Adult U.S. citizens