Fill out the Free Application for Federal Student Aid (FAFSA.) There are three ways to do this: online, by printing out and mailing in the form or by calling the number available on the website. The application period generally starts in January and ends in June for the upcoming school year.
Fill out the financial information in section 2 of your FAFSA using your most recent tax return. You may have to use your parents' return to fill out section 4 if you are a dependent. You do not need to send in your tax return with the application. Your Social Security number is not used to match you with IRS debts. It may be used to ensure that the information you provide on your FAFSA is true and correct.
Wait for notice on your approval status. There are only two debts that will disqualify you from federal student aid: a previous student loan that is now in default or a previous federal grant on which you still owe money. Neither of these have anything to do with debts to the IRS. If you do owe one of these types of debts, you will not be able to receive additional grants or loans until your previous debts are satisfied or no longer in default. If you have a previous loan that is not in default you may still eligible to receive additional aid.