The Culture War Over Sex Markers on IDs Is Causing Chaos. Here’s How We End It

Most people assume sex markers have always been a passport requirement. They weren’t. For decades, travelers got by just fine without them. If they were truly necessary, they would have been included from the start, rather than added in response to cultural anxieties. But the truth is, passports didn’t even include a sex marker until 1977, and when the State Department decided to add one, it wasn’t for security reasons—it was because of a moral panic over gender.

Before the late 20th century, passports in the United States simply didn’t record a traveler’s sex. In fact, the government had already acknowledged that people sometimes changed their names for reasons “suggestive of a change of sex” as early as 1971. The system worked fine without a sex marker, but then something changed: fashion. As unisex clothing and hairstyles became more common in the 1970s, some government officials worried that border agents might have a harder time telling who was a man and who was a woman just by looking at them. And so, in response to shifting cultural anxieties rather than any actual security risk, sex markers became a permanent feature of U.S. passports. As Northeastern University professor Craig Robertson put it, “I sometimes joke David Bowie caused M/F sex markers to be added to the passport.”

That means sex markers on passports were never about stopping fraud, ensuring safety, or helping people prove their identity. They were about making sure travelers fit neatly into one of two government-approved categories. Over the years, those categories became battlegrounds in their own right. By the early 1990s, trans people were allowed to change their sex marker on a passport, but only if they provided proof of surgery. In 2010, Secretary of State Hillary Clinton eliminated the surgery requirement, making it possible for trans travelers to update their passports with a doctor’s note instead. And in 2021, the first U.S. passport with an “X” marker for nonbinary people was issued after intersex military veteran Dana Zzyym won a yearslong legal battle to make that option available.

Then, in 2025, the Trump administration forced the country back into an unnecessary fight over identity, erasing progress and re-imposing outdated gender rules. Their order mandated that all passports reflect the sex assigned at birth, eliminating the 'X' marker option and erasing the progress that had been made. This decision sparked immediate legal challenges, with advocacy groups arguing that the policy violated constitutional rights to privacy and equal protection. The government had spent decades slowly loosening the rigid gender requirements of official documents, but this move brought the U.S. back to the same anxieties that led to sex markers being included in the first place. It’s not about security—it never was. It’s about forcing people into a category, whether it fits them or not.

If that sounds familiar, it’s because governments have always been obsessed with categorizing people, even when those categories serve no real purpose beyond upholding outdated norms. When the government decides who belongs in which category, it is often less about ensuring accuracy and more about maintaining rigid social structures. In apartheid-era South Africa, ID numbers contained a racial classification digit, used to enforce segregation. The government removed those numbers in 1987, recognizing that the racial classification system was an instrument of discrimination. In Rwanda, national ID cards listed whether someone was Hutu, Tutsi, or Twa—until the genocide of 1994, when the government stopped collecting that data to prevent further violence. Indonesia, too, once included ethnic group information on national identity cards, but later abandoned the practice to prevent discrimination.

Trans people already face significant discrimination when it comes to legal recognition of identity. A 2023 study found that trans travelers are four times more likely to be flagged for additional screening at airport security, and nearly half of trans people who have used identification with a name or gender marker that doesn’t match their presentation have been harassed as a result. Making passports less reflective of trans people’s actual identities only increases the likelihood of those encounters.

Passports exist to confirm identity, not reinforce rigid classifications. So why does the government still require an M or F? Sex isn’t always binary—intersex people exist, and biology is more complex than a simple M or F. Medical and hormonal changes can significantly alter a person’s physical traits. If accuracy were the goal, the government would recognize that sex markers are an unreliable and unnecessary disclosure of personal information—they can change over time, unlike fingerprints or facial recognition. Sex classification on official documents also raises significant privacy concerns—why should the government mandate disclosure of someone’s genitals at birth?

We’ve seen this before—governments refusing to let go of outdated identity markers, long after they stopped making any sense. South Africa, Rwanda, and Indonesia eliminated racial and ethnic markers from identity documents when those classifications proved to be instruments of discrimination rather than useful tools. Other forms of identification, like biometric passports and driver’s licenses in some jurisdictions, have evolved to rely more on biometric data rather than sex markers—proving that gender classification is unnecessary for verifying identity. Sex markers on passports have outlived their original purpose because that purpose was never legitimate in the first place. They are the remnants of an outdated moral panic. And it’s time to let them go.