Comment by ForHackernews

Whether you get to vote in local and state elections depends on whether you declare yourself to have moved abroad indefinitely or temporarily (e.g. study abroad, temporary work posting) - https://www.votefromabroad.org/faqs/FP7

But all US citizens (even those born overseas who have never resided in the US) are eligible to vote in federal elections, not just the Presidency but House and Senate races.