The IRS asked me to send in my military orders to confirm my combat deployments in 2016. I have never had to donthis before. Why are they asking?

I don't know, and I'm a Vet myself.  You weren't clear when/why/where you got this notification, so I'll run a few situations that cover all bases.  In the end...confirm who you're talking to by reaching out to them.

• Were you told this by the TurboTax service while preparing your return?
• If so, then do so.  It's not often this happens, but there are some situations when it's necessary.  We'll walk you through things.
• Were you told this by the IRS communicating to you directly by mail or e-mail?
• If Mail:  If the letter is legitimate, contact them telephonically on a secure line to find out more.
• If eMail:  I'd contact them through direct contact numbers/forms on their site at www.IRS.gov to confirm they reached out to me with the letter, and explain the situation.
• If phone:  Same as email.  Confirm and go from there.
• Did you receive this before or after you successfully filed your return?
• Yes:  This increases the likelihood it's a legitimate communication by the IRS.
• No:  Be careful, contact them through direct contact numbers/forms on their site at www.IRS.gov...

I don't mean to sound alarmist, only cautionary.  I look out for my Service Members.

If this helped you, please up-vote this answer so I know you were taken care of 100%. If we need to work together further to get it resolved, please comment...we'll get it taken care of together.

I'm here to help.

For the tax year W-2 in question....if you have a code Q in box 12 on your actual paper W-2 form from DFAS, then it shouldn't be a problem, but you'll still need to respond to the IRS.  (again, assuming the communication was really from the IRS).

And, we sometimes do have to recheck.....but the state tax authorities are not the "IRS" and shouldn't be referred to that way......just to make your situation clear if your letter was from the state.