Transgender
One effort to quantify the population gave a "rough estimate" that 0.3 percent of adults in the US are transgender, overlapping to an unknown degree with the estimated 3.5 percent of US adults (1-in-30) who identify as LGBT. More recent studies released in 2016 estimate the proportion of Americans who identify as transgender at 0.5 to 0.6%. This would put the total number of transgender Americans at approximately 1.4 million adults ().
Voter ID laws in the United States
A 2018 study by the Williams Institute found that 137,000 transgender people who have transitioned will be eligible to vote in the 2018 US election in states with strict voter ID laws. An estimated 57% of them may not have identification or documentation that accurately reflects their gender. Eight states currently have strict voter ID laws that require voters to provide a government-issued photo ID in order to vote at the polls. In these states, election officials and poll workers decide whether a voter's identification accurately identifies the voter and matches the information listed in the voter registration rolls.