Follow-to-Join is the process that allow applicants to immigrate to the U.S. after the principal applicant. Follow-to-Join case is when applicants decided to follow the principal applicants to the U.S. at a later date.
The other applicants on the petition that did not immigrate with the principal applicant can have their cases/visas processed until the principal applicant becomes a U.S. Citizen. Upon receiving these cases from NVC, Post contacts the applicants to schedule them for an interview. For example, you have a child that did not obtain permanent residence at the same time you did, he/she may be eligible for follow-to-join benefits. This means that you do not have to submit a separate Form I-130 for your children. In addition, your children will not have to wait any extra time for a visa number to become available. In this case, you may simply notify a U.S. consulate that you are a permanent resident so that your children can apply for an immigrant visa.
Your children may be eligible for following-to-join benefits when the relationship existed at the time you became a permanent resident and still exists and you received an immigrant visa or adjusted status in a preference category.