Because your father pays alimony, he is considered to be a part of your family’s life. Your mother earns no money, so your father is the one who supports you most. He is your parent for FAFSA, and his income information is needed. If the reason you have not been in contact with your father has to do with escaping abuse, you can appeal to each school, requesting that they use your mother’s information. This is determined on a case by case basis by each school, and documentation by outsiders (counselors, doctors, clergy, legal documents, etc) will be required. Note that a choice not to see or talk to your dad - either by you or by him - isn’t reason enough to waive the requirement that his information be provided. The alimony points to involvement in the family.