What is the I-539 for?
The visa is the stamp you entered with; the status is the permission to stay, with the date shown on your I-94 record. The I-539 is about status, not the visa.
The official instructions list which categories can be extended or changed with this form and which cannot, and ask that it be filed before the I-94 expires.
When several family members request the same thing, each additional one goes on the I-539A supplement. Whether your category allows the change is a legal question we do not answer.
Who usually files it?
- According to the USCIS instructions: a B-1 or B-2 visitor asking to stay longer than the time granted at entry.
- According to the USCIS instructions: the spouse or children of someone on a work or student visa, asking to extend or change their dependent status.
- According to the USCIS instructions: a person who wants to move from one temporary category to another, such as visitor to student, where the instructions allow it.
These are the situations the official instructions describe. Paso Libre does not decide whether any of them is yours.