Colorado State tax has calculation issue for large charitable donations

[cbiros]

As I enter my charitable donations, both my federal and colorado state tax that I owe decrease. However, when I cross the $14902 threshold, my colorado tax suddenly jumps by $634, but the federal tax still decreases.  So, for $14902, my CO tax owed is $278.  When I increase my donation to $14903, it jumps to $912.

[ErnieS0]

You may have an itemized deduction addback.

For taxpayers who have federal adjusted gross income exceeding $400,000 in tax year 2022, if those taxpayers claimed itemized deductions on their federal return, they may be required to add back itemized deductions over a certain amount in this line.

If the filing status for your federal return was single, married filing separately or head of household AND 

• Your federal adjusted gross income as reported on line 11 of Federal Form 1040 exceeds $400,000 AND
• Your claimed itemized deductions on line 17 on Schedule A of Federal Form 1040 AND
• Those itemized deductions on line 17 exceed $30,000
• You must subtract $30,000 from the amount you reported on Line 17 of Schedule A and enter the result on line 4 of this form.

If the filing status for your federal return was married filing jointly AND

• Your federal adjusted gross income as reported on line 11 of Federal Form 1040 exceeds $400,000 AND
• Your claimed itemized deductions on line 17 on
• Schedule A of Federal Form 1040 AND
• Those itemized deductions on line 17 exceed $60,000
• You must subtract $60,000 from the amount you reported on Line 17 of Schedule A and enter the result on line 4 of this form.