It depends on how old they are. If he or she is under 24, they can make any amount and still be your dependent based on the facts you describe.
However, if they are 24 or older, they cannot be a dependent whether or not a student because their income exceeds the threshold of $5,050 for 2024.
If under 24 and you aren't able to claim them, revisit the entry in the "My Info, Your household" section. Make sure all the interview screens have been completed accurately:
Also, they will not qualify for the child tax credit, but he may qualify for the $500 credit for other dependents, if he or she is a dependent.
Here is some more detailed information: Rules for Claiming Dependents on Taxes
If your college student is younger than 24 you can claim him as a dependent. He can file his own tax return to seek a refund of any federal or state tax withheld but must say on his own return that someone else can claim him as a dependent.
There are two types of dependents, "Qualifying Children"(QC) and Other ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, student status, a relationship test and residence test.
A child of a taxpayer can still be a “Qualifying Child” (QC) dependent, regardless of his/her income, if:
So, it doesn't matter how much he earned. What matters is how much he spent on support. Money he put into savings does not count as support he spent on himself.
See full dependent rules at: https://turbotax.intuit.com/tax-tools/tax-tips/Family/Rules-for-Claiming-a-Dependent-on-Your-Tax-Return/INF12139.html