You may need to re-register if your address, party affiliation, or name has changed since you last registered.
Many states require you to register to vote in advance of the election.
Make sure you are up-to-date with your voting rights and election information.
To vote from abroad, you must register with local election officials in your state of voting residence AND request an absentee ballot. You can use the Federal Post Card Application (FPCA) to do both. Submit a new FPCA early each year, every time you move, and whenever you change your address, email, or name. See more information here.