I’m going to be overseas deployed for over 1/2 of this year. I also received a bonus and was taxed 2700 on it can I claim this on my refund to get it back?

[Opus 17]

If you are a US citizen or green card holder, you owe US tax on all your world-wide income, no matter where you were living when it was paid.  If you also pay tax in a foreign country on the same income, you can claim a deduction or credit on your US tax return to reduce the double-taxation.

Tax withholding on bonuses is controlled by a specific IRS formula that sometimes (but not always) overestimates the tax on the bonus.  At the end of the year, you file one tax return that lists all your income and all your withholding, and calculates your total tax bill.  If your withholding was more than your tax bill, you get the difference as a tax refund.  There is no way to apply for a refund in the middle of the year, due to a bonus or any other reason. 

[TomD8]

A military bonus is taxable just like your regular military pay, unless it falls under the combat zone exclusion.  The combat zone exclusion is detailed in this federal statute:

https://www.law.cornell.edu/cfr/text/26/1.112-1#:~:text=CFR-,%C2%A7%201.112%2D1%20Combat%20zone%20co....

In short, money earned while you are serving in a combat zone is tax-free. This can include your reenlistment bonus, provided you signed the reenlistment paperwork while you were in the tax-exempt combat zone. This also covers your annual installment bonuses, even if they are later received when you are no longer serving in the tax-exempt combat zone.

However, if you signed the paperwork outside the combat zone, it is not tax-exempt, even if you receive the bonus or annual installment while you are in the combat zone.