I'm in the military and got a 1099-MISC for my bonus enlistment... Turbo Tax is telling me I need to pay BACK part of the bonus. This doesn't sound sound right. help?

No, you do not have to give any back.

Is it in Box 7? If so, it is considered self-employment and is entered on Schedule C. 

If it is Box 3:

1. Sign in to TurboTax Online, click Continue your return, then pick up where I left off (if you are using TurboTax CD/ Download, then just open your return on your computer).

1. Click on Federal Taxes at the top of the screen.
2. At the bottom of Your Income box pick the option in blue to help me add other income, then jump to full list;
3. Scroll down the page to the last section titled: Less common Income and click show more;
4. Select start or update next to the last topic titled Miscellaneous Income, 1099-A, 1099-C;
5. Scroll down to the last option titled Other reportable income and select start or edit;
6. When it asks, "Any other reportable income?" say yes then type in a description and the amount to report it on your tax return.

This will place it on "Other Income" line of your Form 1040