Although a parent can claim a dependent up to the age of 19 they still must be a qualifying dependent so if the child did not live with the parents for more than 1/2 the year AND the child was self supporting they cannot claim the child. So the 17 year old may file their own return and claim a dependent of their own.
You can claim a child, relative, friend, or fiancé (etc.) as a dependent on your 2022 taxes as long as they meet the following requirements:
Qualifying child
- They're related to you.
- They aren't claimed as a dependent by someone else.
- They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
- They aren’t filing a joint return with their spouse.
- They're under the age of 19 (or 24 for full-time students).
- No age limit for permanently and totally disabled children.
- They lived with you for more than half the year (exceptions apply).
- They didn't provide more than half of their own support for the year.
Qualifying relative
- They don't have to be related to you (despite the name).
- They aren't claimed as a dependent by someone else.
- They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
- They aren’t filing a joint return with their spouse.
- They lived with you the entire year (exceptions apply).
- They made less than $4,400 in 20222.
You provided more than half of their financial support
