What are the requirements to claim a child on your taxes after 18 years of age?

To claim a child on your taxes after they turn 18, they must be a full-time student under the age of 24 and live with you for more than half the year. Additionally, the child must not provide more than half of their own financial support. If the child does not meet these criteria, you cannot claim them as a dependent. Always verify specific tax laws or consult a tax professional, as requirements may vary.