Colorado taxable income

For the calculation of Colorado income tax, an individual’s federal taxable income must be modified as required by Colorado law. Most individuals must prepare IRS Form 1040 or IRS Form 1040-SR to determine their federal taxable income. Additional federal forms, such as IRS Schedule 1 and IRS Schedule A, may also be required to compute an individual’s federal taxable income.

Modifications to federal taxable income required by Colorado law include both additions and subtractions. Part 3 of this publication discusses required additions to taxable income. Allowable subtractions are described in Part 4.