Has the proportion of Americans identifying as transgender increased in the last decade?
A 2019 paper by three New York University researchers estimates that the proportion of adults who identify as transgender has increased from about .03% of the U.S. population to about .06% in the last decade. It also finds "a higher proportion of [transgender non-binary] identities among the younger generations."
A 2017 study by UCLA's Williams Institute estimates 0.73% of teens aged 13 to 17 identify as transgender. The study found "the population of individuals who identify as transgender appears similar to the U.S. general population in regard to age"—i.e., 8% of the U.S. general population is 13 to 17 years old and, comparably, 10% of the U.S. transgender population is 13 to 17 years old.
A 2017 Centers for Disease Control survey of select states and school districts found that 1.8% of surveyed high-school students identify as transgender.