This answer is from Step mom on my dads tax return?
Unfortunately, the FAF forms doing distinguish between step mom and bio mom. Your dad is remarried and their financial obligations (assets, debts and income) are shared jointly. You can append a note to the FAF form you send into the specific colleges, to try to explain the situation, although under the Federal rules, your step and bio parent are tied together.
Mark Kantrowitz replied about a month ago
Your information is dated. The FAF (Financial Aid Form) and FFS (Family Financial Statement) ended with the introduction of the FAFSA in 1992. The FAF has since been replaced with the Financial Aid PROFILE.
You also cannot append a note to the FAFSA; rather, you could ask a college separately for a professional judgment review. Such a review will not, however, change the treatment of stepparents as that is a matter of federal law. It's only if there's an unusual circumstance (say, your step mom has a protection from abuse order against your dad but has not yet had the opportunity to get a divorce, or your step mom has just been incarcerated or institutionalized) that they'll make an exception to this federal requirement.
