Start with your adjusted gross income, the figure on the last line of the front of your 1040 or 1040A tax form. Then add back:
- Deductions for IRA contributions.
- Deductions for student loan interest or tuition.
- Excluded foreign income.
- Interest from EE savings bonds used to pay higher education expenses.
- Employer-paid adoption expenses.
Things you don't have to add to the AGI:
- Contributions to employer-sponsored plans, like 401(k)s.
- Taxable income generated by converting to a Roth IRA.