The second page of the 1040 starts off with the adjusted gross income (AGI) that was calculated on page one. This figure is used to calculate the various deductions and credits on page two. If it is over certain thresholds, deductions and credits will be reduced. Deductions on page one (often referred to as 'above-the-line' deductions) favor the taxpayer who does not itemize deductions on line 40a as well as higher income taxpayers who are affected by limitations due to high AGIs...
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“Before I came here, I was confused about this subject. Having listened to your lecture, I am still confused -- but on a higher level.”
- Enrico Fermi, Italian American physicist 1901-1954