My younger sibling will begin attending college two years after me, meaning there will be two years of overlap. For financial aid, should I list this as another family member attending college at the same time? How will this affect my costs?
You fill in the FAFSA every year. If your sibling is not in college yet, then you shouldn't mention that another family member is attending college at the same time. So, let us just say that you are about to be a college freshman. So, when you fill out your FAFSA, no other member is attending college at the same time. When you are a college junior, your sibling will be a college freshman. When your fill out the FAFSA during your junior year in college, you should then say that another family member is attending college at the same time. Hope this helps!
You file FAFSA every year so until they enter college you don't but when you talk to aid office mention it as it would affect your need. Hope this helps.
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Yes, as @DebaterMAX said, you should definitely mention it on your application when your sibling will be starting college. There is a specific question on these financial aid forms for this. I can't predict exactly how it will impact your aid, but you could toy around with the net price calculators to get a better idea!