I am a Department of the Army civilian working outside the U.S. on a 3 year assignment. Does that qualify for the foreign income credit or is it considered a deployment?

It depends.

No - If you are working for the US government and getting paid by the US government, then your income is considered US-sourced income (regardless of where the work is performed in the world). This income will NOT qualify as foreign income and you will not be able to claim a foreign earned income exclusion on these earnings.

Yes - If you earn income outside the USA from work that you perform that is NOT being paid by the US government (foreign source income) and you meet  the Bona Fide Residence Test or the Physical Presence Test, you might be able to claim an IRS - Foreign Earned Income Exclusion that would exclude a portion of your foreign source earned income (up to $101,300 for 2016).  TurboTax will guide you on taking the foreign earned income exclusion when you enter your foreign source income under Federal Taxes> Wages and Income>I'll choose what I work on (or jump to full list)> Less Common Income (show more)> Foreign Earned Income and Exclusion.

Use this IRS link for more information about US Citizens and Resident Aliens Living Abroad