As a green card holder you can bring some close family to live in the US. The steps are clear, but there is usually a wait.
F2A: your spouse and unmarried children under 21.
F2B: your unmarried sons and daughters aged 21 or older.
You cannot sponsor parents, brothers and sisters, or married children. Only US citizens can. Your parents can still visit you on a B-2 visa.
If an F2B son or daughter marries before getting the green card, the case usually ends.
File Form I-130 (Petition for Alien Relative) with USCIS. Online or paper.
File one I-130 for each person you sponsor.
Add proof: a copy of your green card, a marriage certificate or birth certificate, and for a spouse, proof the marriage is real (photos, joint accounts, messages).
Fee: the current USCIS fee schedule lists $625 online and $675 on paper per petition. Check uscis.gov/g-1055 first.
The date USCIS receives it is your priority date, your place in line. It is on the receipt notice.
Step 2: The wait and the Visa Bulletin
Each year only a limited number of F2A and F2B green cards are given. The State Department publishes the Visa Bulletin every month at travel.state.gov.
Find your category (F2A or F2B) and your relative's country of birth.
If your priority date is earlier than the date shown, a visa may be available.
F2A usually moves faster than F2B. F2B can take many years, and some countries of birth wait longer than others.
Step 3: Affidavit of Support (Form I-864)
When the visa is close, you sign Form I-864. It is a promise to the US government to support your relative.
You must show income of at least 125% of the federal poverty guidelines for your household size. The current amounts are on Form I-864P at uscis.gov.
If your income is too low, you can use assets or a joint sponsor (another person who meets the income rule).
It is a legal contract. It usually lasts until the relative becomes a citizen or has worked about 10 years (40 quarters) in the US.
When you become a citizen
Your spouse and children under 21 become immediate relatives. There is no yearly limit, so the wait is usually much shorter. The petition changes automatically; tell USCIS or the National Visa Center and send proof of citizenship.
An F2B case moves to F1 (unmarried adult children of citizens).
You can then file for parents (if you are 21 or older), brothers and sisters, and married children.
Not updating your address. A missed letter can delay the case for years.
Long trips abroad that put your own green card at risk.
Assuming you can sponsor parents now.