The CT 1040, pages 3 & 4 handle subtractions to CT income. Line 48b calculates 28% of pension or annuity income. If your federal AGI is $75,000 or more ($150,000 if MFJ) then no deduction is allowed. The program should calculate it for you. See How do I preview my TurboTax Online return before filing?

are you certain about the $150,000 if MFJ? Turbotax isn't calculating this 28% subtraction for me on our CT 1040 and our Federal AGI is $110,000 (MFJ )

According to this  website, the income limits are $75,000 for single taxpayers and $100,000 for couple filing jointly.

that's correct -- that's the info published in "CT-1040-Online-Booklet_0221.pdf" ($75k single, $100k MFJ federal AGI amount)