The question is asked in the Personal Info section of Turbotax. Open your return and click Personal Info. On the page Your personal summary, scroll down and click the Edit button to the right of your name. On the next page Your personal info, look down to where you put your occupation. Right below that line you should see the line:
I am a member or former member of the U.S. Armed Forces (active, reserve or National Guard).
Select YES and on the next page you should see:
Your name, what was your military status as of December 31, 2016?
Active duty military
Reserves
National Guard
Former member (retired, veteran, etc.)
Select whichever applies to you like Former member. Now you are listed as Retired Veteran.