Hiding midway through the FAFSA, you'll find the question relevant to getting your AmeriCorps income to NOT count against you for financial aid.
On the paper version of the 2013-14 FAFSA, it's easy to find: Question 43D.
It’s trickier to find the question when filling out the FAFSA online. When you reach a screen labeled “Student Financial Information Continued,” you should see a number of check boxes. Click the checkbox next to the text, “Grants and scholarship aid reported to the IRS.” When you click the box, this text should appear:
Student grant and scholarship aid reported to the IRS in your (and your spouse’s) adjusted gross income. Includes AmeriCorps benefits (awards, living allowances, and interest accrual payments), as well as grant and scholarship portions of fellowships and assistantships.
Make sure you fill this out! It can help you get a better financial aid package than if you just leave it blank.
Though you won't get the satisfaction of doing the math yourself, when you submit your FAFSA, the financial aid office will subtract the amounts you list in this section. This gives you a lower adjusted gross income.
In other words, if your only source of income in the previous calendar year is $9,000 from AmeriCorps or VISTA, then for financial aid purposes your income is $0, and you potentially could receive a better financial aid package than a student who earned $9,000 at a regular job. (Be aware that other factors may apply here -- for example, if your parents still claim you as a dependent or if you have other assets.)
The potential benefits can stretch into two school years. The FAFSA you fill out for the 2013-14 school year is based on your 2012 taxes. Likewise, down the road, the FAFSA you fill out for the 2014-15 school year will be based on your 2013 taxes. If your term of service runs from 2013-14, you can potentially receive benefits from this section of the FAFSA over the next two school years. Even if you take a year off national service before going to school, you might still be able to benefit.