You may have received some refundable credits which would raise your refund. If you had Itemized Deductions, that could also raise your refund.
Some Examples of refundable credits are:
- American opportunity tax credit. Available to filers who paid qualified higher education expenses.
- Earned income tax credit. Paid to eligible moderate- and low-income working taxpayers.
- Child tax credit. Available to families with qualifying children under age 17.
- Premium tax credit.
