Overview
The computation of your New York State income tax is based on your New York adjusted gross income. Your New York adjusted gross income is your federal adjusted gross income after certain New York additions and New York subtractions (modifications).
New York State taxes certain items of income not taxed by the federal government. You must add these New York additions to your federal adjusted gross income.
Similarly, New York State does not tax certain items of income taxed by the federal government. You must subtract these New York subtractions from your federal adjusted gross income. See below and Form IT-225 , New York State Modifications , and its instructions .