Dependent students must report their parents information, as well as their own, on the Free Application for Federal Student Aid (FAFSA) form. 
Find out who counts as your parent when you file your FAFSA form. If you are considered a dependent student for FAFSA purposes , you will need to provide information about your legal parent on the application. A legal parent is your biological or adoptive parent, or your legal parent as determined by the state for example, if the parent is listed on your birth certificate. If you have a stepparent currently married to your legal parent , you generally also must provide information about him or her. View text-only version 

Who is my parent according to the FAFSA form? 
If you need to report parent information , here are some guidelines to help you : If your legal parents your biological and/or adoptive parents, or parents as determined by the state [e.g., a parent listed on your birth certificate] are married to each other, answer the questions about both of them, regardless of whether your parents are of the same or opposite sex. If your legal parents are not married to each other and live together , answer the questions about both of them, regardless of whether your parents are of the same or opposite sex. If your legal parent is widowed or was never married , answer the questions about that parent. 

What if my parents are divorced or separated? 
In this case , how you fill out the FAFSA form depends on whether your parents live together or not. Keep the following in mind as you read this section : For FAFSA purposes , your married parents are separated if they are considered legally separated by a state, or if they are legally married but have chosen to live separate lives, including living in separate households, as though they were not married. When two married persons live as a married couple but are separated by physical distance or have separate households , they are considered married for FAFSA purposes. 

Divorce

user: Hi there. I'm looking some help related to the information I need to provide on my student aid loan apply form, about me and my parents.

assistant: Sure, no problem. You need to have present who counts as your parents when you file your fafsa form.

assistant: Are you dependent of your parents?

user: Not, pretty much, that's why I have some doubts about it.

assistant: Ok, no problem.  There is a stepparent currently married to your legal parent?

user: Yes, that's right, Is that important?

assistant: Yes, in that cases, you need to provide the information of him or her too.

user: And what happens if I can't provide some this information?

assistant: Depending of the circumstances, you may be able to submit your fafsa form without some of your parent information despite being considered a dependent student. Did you know that?

user: I have kinda heard about that, but I wasn't very sure.

assistant: Is any of your parents incarcerated?

user: Yes, that's right.

assistant: In that case you can provide your fafsa form with some the information related to your parents.

user: Do I have to say which of them is on jail?

assistant: Is not necessary, the fafsa form use gender neutral terminology, for this kind of cases, So it don't really matters.