Can parents apply for immigration of married children together or one by one?

Applicants for relative immigration can be American citizens or permanent residents of the United States. American citizens can apply for immigration for spouses, children, parents and siblings; Permanent residents can apply for immigration for spouses and unmarried children.

IR relative migration

This kind of relative immigration is used for unmarried children under 2 1 year old of spouses of American citizens and American citizens over 2 1 year old who apply for immigration for their parents. The biggest advantage of this kind of immigration is that there is no quota limit and the speed of handling cases is faster.

B. Priority categories of relatives' migration

The first priority category (F 1), adult unmarried children of American citizens;