You shouldn't make this $0 by going into the forms. Instead edit this in the Education Information section of step-by-step by following TurboTaxMarilyG advice above. Note if you are claiming the American Opportunity credit, you enter $4000 since you can't double-dip 529 and American Opportunity Credit. Same goes for Lifetime Learning which is up to $10,000. Really, TT should fill in these amounts based on what credit you are getting but they don't.
