Are enlistment orders an acceptable form of documentation from the servicemember to invoke the interest rate benefit

http://www.military.com/benefits/content...-questions.html

I'm former military (20yrs) - this site is pretty reliable.

Certainly they are. A key here is that when a reservist is called up and the orders are for a date in the near future, they're effective now. A person who enlists is covered when they report - i.e. the date the orders have them "employed."

As an example, I enlisted 8 months before I reported. I wouldn't have been covered until I reported. If I was now a reservist and I got orders to deploy in Feb. I would be covered now.