If you are single and would have a modified adjusted gross income (MAGI) greater than $65,000, it would be beneficial to contribute the amount to the 401k that would help you optimize the student loan interest deduction on your taxes.
The deduction phases out when your MAGI is greater than $65,000 and is eliminated entirely when your MAGI is greater than $80,000.
For example, if you earn $80,000 per year and contribute at least $15,000 to your 401k, you can reduce your MAGI enough to qualify for the full deduction of the amount of interest paid, up to $2500.