From FAFSA website:
Dependency Status Determination
A few words on dependency: dependency in financial aid is significantly different than dependency for tax purposes. Here are the criteria for whom the Department of Education classifies as an independent student. If you do not meet any of these criteria, then you are classified as a dependent student for the purpose of your financial aid application. Note: Your FAFSA status is not the same as your tax filing status.
You were born before January 1, 1990
You are or will be enrolled in a masters or Doctoral degree program at the beginning of the school year
You are married on the day you file your FAFSA
You are a parent
You have dependents other than your spouse who live with you and who receive more than half their support from you at the time you apply
Both your parents are deceased (or were until age 18) a ward of dependent of the court
You are currently serving on active duty in the U.S. Armed Forces for purposes other than training
You're a Veteran of the U.S. Armed Forces
You were a foster child after the age of 13
You are an emancipated child as determined by a court judge
You are homeless or at risk of homelessness as determined by the director of a HUD approved homeless shelter, transitional program, or high school liaison