Can I itemize on my Colorado return if I claimed the standard deduction on the federal return? No. CO instructions indicate the state taxable income is pulled from the federal return where your deductions have already been considered. Related articles What is my residency status for Colorado? Is my retirement income taxable to Colorado? Can I itemize on my Connecticut return if I claimed the standard deduction on my federal return? How do I change my Prior Year return after it has been accepted by the IRS?