I am over 65 and have significantly more annuity income than the $24,000 allowed annuity income subtraction. This larger amount is reported as taxable on my Federal income form. However, Turbotax tells me I can only subtract 19,000 on my 1040AD form. I cannot change this to the maximum amount on the form. Turbotax does not give me any explanation for this. I have read all the instructions for filling out Colorado form DR0104AD and I see no reason not to be able to subtract this amount.
Yes, tax law changes allow you to exclude the full amount of taxable Social Security from your Federal return, which you will see on Line 3 of Form 104AD.
On the Pension and Annuity Exclusion Worksheet, the Allowable Pension Exclusion amount on Line 6, is the smaller of the sum of Lines 1c, 2c, and 4, or the limit of 24,000 if over 65, reduced by the amount of the Social Security Exclusion. This may account for the difference in the amount you are expecting.
This transfers to Line 4 on the 104AD.