If you are an American living outside of the U.S., you need to request your ballot for the federal election by October 8, 2016 (in most states), even if you are already registered to vote. 

Do it. Now.
If you don’t know how to register to vote or request a ballot from abroad, then read on.
How to vote in U.S. elections from abroad.

Earlier this year, when the U.S. presidential campaign was just starting to heat up, I started to feel quite guilty about the fact that I have never voted. Having moved so often since the age of 18, it just always seemed so complicated and difficult. I was also kind of lazy.

But now I have taken the first step to changing that: I registered to vote.

I always assumed registering from abroad would be complicated, but my home country pleasantly surprised me! Here is how I registered to vote from Germany:
1. Visit FVAP.gov
 FVAP is the Federal Voter Assistance Program for service members and other overseas citizens. This is the first stop for any overseas citizens that want to vote, whether you are already registered or not. 
2. Choose Your State
Voting procedures vary by state, so you will need to choose your state from the drop-down menu on the website.
3. Follow the Directions
Yeah, it’s that easy. Creating a numbered list probably wasn’t necessary…
When I was registering to vote, I was worried that I would have to spend a lot of time and money mailing registration materials back and forth between the U.S. and Germany. However, Illinois actually has a website that allowed me to download the forms, fill them out electronically, and email them to my local county clerk.
The hardest part was having to answer this question:The hardest question for an expat.
Can any expat really answer this question with complete certainty? Anyways, your answer will only effect whether or not you can vote in local elections as well as federal elections.
After sending my voter registration and ballot request form by email, I then periodically checked the website to see if my application was approved. Once it was approved, I received my ballot shortly thereafter.
If you are already registered to vote, remember that you still need to request a ballot for this election. 

If you are still feeling confused, here are some other resources to help overseas American citizens vote:
Let me know if you are voting in the comments below!