In 2016 I got a reenlistment bonus of $9100 and only received $6279 due to taxes and I am wondering if it is possible to get any of it back from the federal return.

[firesidethunder]

The bonus was taxed about 25% which is around $2275.

[Hal_Al]

You will get some of that back.

You did not "already pay tax". What you paid was only withholding, an estimate of the tax  due. No piece of income is taxed individually. All your income,enlistment bonus, is added together at tax filing time. The tax is calculated on that total (after adjustments, deductions, exemptions and credits). Then withholding is subtracted to determine if you owe more or get a refund. The enlistment bonus is already included in box