The F2A visa process begins when you submit a petition for your family members. All the information needed before starting your application process is listed in the F2A Visa bulletin.
After reviewing your I-130 Form, the USCIS will communicate its decision. If your petition has been approved, your documents will be delivered to the NVC (National Visa Centre).
The NVC will send the approval documents to both the petitioner and your family. If your petition exceeds the limit of the number of visas guaranteed, your application will be processed the following year. Otherwise, your family will be asked to fill out a DS-260 Form (Immigrant Visa Electronic Application).
Your relatives must be able to explain the reasons why they are immigrating and undergo a medical examination at a licensed doctor. The NVC will send you all the information about what check-ups you must complete, as well as a list of all the mandatory vaccinations.
If the U.S. Embassy approves your visa, you will also receive an envelope with further instructions.