How to vote while abroad: Here's your complete overseas voting guide for the 2016 election

AP

If all the Americans living abroad were placed in one state, it would be nearly as populous as Virginia. That's according to the Association of Americans Resident Overseas, which state there are 8 million American citizens living overseas. 

These voters represent a large block of potential support for presidential candidates. Both Democrats Abroad and Republicans living overseas weighed in during the primaries. Bernie Sanders' brother Larry drew attention to the voting group when the Vermont Senator's older brother gave a tearful speech in favor of Bernie's nomination at the Democratic National Convention. Larry Sanders lives in England.

Americans living outside the country have the same rights to participate in elections as current U.S. residents. And the requirements are similar — state-by-state voter registration deadlines still apply — though Americans living out of the country must vote absentee. 

A U.S member of Combined Joint Task Force-101 walks past an election banner at a US military base in Bagram north of Kabul, Afghanistan, Oct. 15, 2008.  Soldiers, aid workers and military contractors in Afghanistan filled out absentee ballots that year. Source: Rafiq Maqbool/AP
A U.S member of Combined Joint Task Force-101 walks past an election banner at a US military base in Bagram north of Kabul, Afghanistan, Oct. 15, 2008. Soldiers, aid workers and military contractors in Afghanistan filled out absentee ballots that year.  Rafiq Maqbool/AP

To vote from overseas, American citizens must fill out the Federal Post Card Application and mail it to their local election officials. If everything checks out, citizens will receive an email with a blank ballot or a paper ballot through the mail. 

States must send ballots out at least 45 days before federal elections. That means this year, absentee ballots for overseas voters should be sent out by Saturday, September 24. 

James McGuire, of Northampton, Massachusetts, casts his vote at a polling station in Rome, Italy, Tuesday, Feb. 5, 2008, set by Democrats party supporters for the Democratic Primary election on "Super Tuesday." Democrats living overseas had a rare chance to vote in the first-ever global primary to choose the Democratic nominee for President in the coming Nov. 2008 U.S. Presidential elections. Source: Andrew Medichini/AP
James McGuire, of Northampton, Massachusetts, casts his vote at a polling station in Rome, Italy, Tuesday, Feb. 5, 2008, set by Democrats party supporters for the Democratic Primary election on "Super Tuesday." Democrats living overseas had a rare chance to vote in the first-ever global primary to choose the Democratic nominee for President in the coming Nov. 2008 U.S. Presidential elections.  Andrew Medichini/AP

To make sure a vote is counted, residents must check with their state to see when ballots have to be postmarked by. Some states only require postmark by a certain date, while others require absentee ballots actually have been delivered by a set date.