No. You can only claim someone 18 years of age or older as an eligible dependant if they have an impairment in physical or mental functions (disability).

So it doesn't matter that they were 17 for half the year? Were high school students until June and turned 18 in June 2023?? Sorry, I just want to make sure I'm entering everyrhing correctly.

Also, does TurboTax recognize that they are over 18 when I put in their birth date?

Yes, TurboTax will calculate the age of the child from the birthdate. If the child was under 18 during the year, you can still apply for the eligible dependant credit.

Sorry, but the first response seems to suggest that if the child turned 18 in calendar 2023 I cannot claim her.   The second suggests, to me, that you can make the claim.   Can you resolve this please?   My child turned 18 December 19, 2023.

@Holmium TurboTax will calculate the age of the child from the birthdate that you enter. If the child was under 18 during the year, you can still apply for the eligible dependant credit.

Just to confirm, you can still claim the child as dependent even if the child turned 18 within the taxation year? 

Yes, TurboTax will calculate the age of the child from the birthdate. If the child was under 18 during the year, you can still apply for the eligible dependant credit.