Turbo Tax says I don't qualify for Student Loan Interest deduction on my parent plus loan but it doesn't say why not. Does anyone know why I may not?

You can claim the deduction if all of the following apply:

• You paid interest on a qualified student loan in tax year 2024;
• You're legally obligated to pay interest on a qualified student loan;
• Your filing status isn't married filing separately;
• Your MAGI is less than a specified amount which is set annually; and
• Neither you nor your spouse, if filing jointly, were claimed as dependents on someone else's return.

Many don't qualify based on being over the income limit.

For 2024, the amount of your student loan interest deduction is gradually reduced (phased out) if your MAGI is between $80,000 and $95,000 ($165,000 and $195,000 if you file a joint return). You can't claim the deduction if your MAGI is $95,000 or more ($195,000 or more if you file a joint return).

The most likely reason is that the loan is not in your name and/or you are no a co-signer.  This means that you are not legally obligated to pay the loan or the interest.  That disqualifies you, from the deduction, even if you pay the interest.