Why does TurboTax determine my qualifying child as non-dependent if they earn more than $5200? I thought the earning limit rule does not apply to qualifying child

[DoninGA]

If the child is age 19 or older, not a full time student, and has income of $5,200 or more then no one can claim them as a dependent.

Is this your situation?

[MindyB]

You are correct that the gross income limit (which is $5,200 for the 2025 tax year) does not apply to a Qualifying Child. However, TurboTax likely flagged your child as a non-dependent because they no longer meet the specific age or student criteria to be considered a "Qualifying Child," causing the software to evaluate them as a Qualifying Relative instead. To be a Qualifying Child, they must be under age 19, or under age 24 if they are a full-time student for at least five months of the year. If your child is 24 or older (and not disabled), or 19–23 and not a full-time student, the IRS switches them to the "Qualifying Relative" category, which strictly enforces that $5,200 income limit. 

If they are a full time student. navigate to My Info on the left of your screen, Your household, select your child's name to expand, then choose "Revisit". Continue through the interview until you  to the screen called "Tell us more about [their name]'s situation." Here, check the first box, Full-time student in 2025.