Why can I not claim my son as Dependant? [pii removed]

[Hal_Al]

Why do you think you should be able to?
If TurboTax is not qualifying you, it's because you don't meet the rules.

[Hal_Al]

There are two types of dependents, "Qualifying Children"(QC) and standard ("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, a relationship test and residence test. Only a QC qualifies a taxpayer for the Earned Income Credit and the Child Tax Credit. They are interrelated but the rules are different for each.

If TurboTax is not qualifying you, it's because you don't meet those rules.

Full dependent rules: 

https://turbotax.intuit.com/tax-tools/tax-tips/Family/Rules-for-Claiming-a-Dependent-on-Your-Tax-Ret...