Millennials now make up over one-third of the American workforce, according to the Pew Research Center. And a large fraction of millennials—perhaps as many as 12 percent, by GLAAD’s latest measure—identify as transgender or gender non-conforming.

Combine those two facts and one thing is clear: Employers are going to have to adjust their approach to gender—and fast.

That means going beyond the guidelines that many companies in the United States have developed for employees who transition from one gender to another—sometimes referred to as “binary” transgender people—in order to accommodate a new wave of non-binary workers who do not strictly identify as either male or female.

What kinds of restrooms will these non-binary employees use? Which gender options will be listed on their onboarding paperwork? Will they feel comfortable in the office?

“These questions are not going to go away,” AC Dumlao, program manager for the Transgender Legal Defense and Education Fund, told The Daily Beast. “They’re only going to get bigger. They’re only going to become more pressing.”

Dumlao, who is non-binary and uses the gender-neutral singular pronoun “they,” says that they advise human resource departments to “take a step back” and examine “the gender binary—how it’s reinforced in your office, and how to take that away.”

“ You don’t want to have a client or a guest come into an office, you don’t want your newly onboarded employee to come into the office, and have everyone stepping on eggshells because they aren’t prepared. ” — AC Dumlao, program manager for the Transgender Legal Defense and Education Fund

Concretely, Dumlao notes, that process involves steps like removing gendered signage from single-stall restrooms or offering employees a “fill-in-the-blank” field for gender on HR documentation. Even if companies do not currently have employees who are openly clamoring for these changes, they will soon.

“It’s better to be proactive rather than reactive,” they said. “You don’t want to have a client or a guest come into an office, you don’t want your newly onboarded employee to come into the office, and have everyone stepping on eggshells because they aren’t prepared.”

Indeed, as several non-binary people told The Daily Beast, coming out as neither male nor female in a corporate setting is no small feat. All of them asked to remain anonymous so as to avoid naming their specific companies.

“I was incredibly nervous and mostly afraid of people not understanding or making any effort to use my pronouns,” said one non-binary editor who works for a remote company, noting that, fortunately, their colleagues have since proved to be welcoming.

“Luckily, the worst thing I’ve faced is ignorance and bureaucracy,” they added.

One American living and working abroad for a company that employs a large number of foreign-born American men told The Daily Beast that he has yet to come out as non-binary, in part because of the questions he would “have to field (in two languages, no less).”

“ My first interaction with everyone I meet is extremely uncomfortable for me, but I’ve got little choice but to bury that feeling and act like nothing’s wrong. ” — American working abroad in the early stages of coming out as non-binary

He is in the early stages of coming out as non-binary, uses male pronouns, and has a masculine name on his name tag that he no longer wishes to be called by.

“So my first interaction with everyone I meet is extremely uncomfortable for me, but I’ve got little choice but to bury that feeling and act like nothing’s wrong,” he said.

Some non-binary people who are out at work choose not to be out to everyone.

One non-binary account planner at a digital advertising agency who uses the gender-neutral pronoun “they” told The Daily Beast that, when they started their current job, they had friends in their office who “already understood my gender and spoke with our team about using my pronouns.” But telling everyone, they say, is not in the cards right now.

“I haven’t necessarily come out in any grand sort of way,” they told The Daily Beast, noting that it would be “an excessive amount of work” to come out company-wide.

“I sort of resigned myself to being out with my team and keeping this aspect of my life private from the rest of the company,” they said.

The coming out process for non-binary workers is complicated by the amount of paperwork that they would have to complete in order to remove their listed male or female gender from company records.

That’s if their employer even allows it. According to the Human Rights Campaign’s Corporate Equality Index, over 450 major businesses now have “gender transition guidelines for employees”—a sign of transgender acceptance, and proof that corporate America is moving faster on LGBT issues.

But those guidelines are not always inclusive of non-binary people—as Dumlao often has to tell HR departments that ask for help dealing with “transitioning” employees.

A company system that would allow, say, a transgender woman to change her honorific from “Mr.” to “Ms.” may not always include a gender-neutral option like “Mx.” for a non-binary person.

A form that a transgender man might use to change his gender from female to male might not have a non-binary alternative.

“ Bathrooms are a thing. Letterheads and HR software use binary genders. Multinational companies have multiple languages and not all have progressed enough to have widely known non-binary pronouns. ” — Non-binary tech worker in the United Kingdom

Indeed, although non-binary people are often included under the larger transgender umbrella, they can pose different challenges to offices than do their binary counterparts.

“On top of needing acceptance, non-binary people need gendered things to be done away with or made optional entirely,” one non-binary tech worker in the United Kingdom told The Daily Beast. “Bathrooms are a thing. Letterheads and HR software use binary genders. Multinational companies have multiple languages and not all have progressed enough to have widely known non-binary pronouns. So much!”

“Aside from gendered restrooms, forms are my greatest nemesis right now,” the non-binary editor told The Daily Beast. “I’m currently listed as ‘female’ in our HR system and the only options are ‘female,’ ‘male,’ and ‘not’ declared—and I cannot change this field myself. I have to contact HR to do so.”

Complicating matters further is the fact that non-binary legal recognition is still in its nascent stages. Many states now allow binary transgender people to change their gender markers on driver’s licenses and birth certificates, with standards of proof ranging from a physician’s note to a surgeon’s letter following sex reassignment surgery.

On a federal level, the State Department and the Social Security Administration both allow transgender people to move from “M” to “F” or vice versa.

But to date, only a small handful of U.S. jurisdictions—mostly on the West Coast—allow non-binary people to apply for an “X” gender marker on state ID.

That means most non-binary workers do not have official government recognition of their gender identity. And even if non-binary people do obtain an “X” on a driver’s license, the federal EEO-1 form still requires their employers to sort them into one of two binary genders.

As Allen Smith, manager of workplace law content at the Society for Human Resource Management, noted in a blog post for SHRM, the EEO-1 survey—which employers must submit to the Equal Employment Opportunity Commission every year to demonstrate compliance with federal civil rights law—“has no place for employees who do not report as either male or female.”

That has made a number of employers reluctant to offer the more expansive gender options that some companies are now offering because, as Smith told The Daily Beast, they “don’t want to stray too far from the EEO-1 form designations themselves.”

If a non-binary employee opts out of providing a gender for the EEO-1 form, their employer—and more specifically, their HR department—must pick a gender for them.

As Smith explained in his SHRM blog post, “if a worker declines to self-identify as male or female, a company still must report a gender for that person.” How that takes place might give many non-binary people pause: “HR may conduct a visual observation of the employee for gender and report in good faith,” Smith wrote.

In short: HR will look at the non-binary employee and then check a box.

The problem with that methodology, says Dumlao, is that it requires companies to assume gender based on physical appearance. (“How a person looks is not a great indication of a person’s identity,” they told The Daily Beast.)

“ Often times, I feel as though I am either completely erasing myself by dressing in what people assume to be women’s clothes—or I am coming off sloppy by opting out of wearing makeup and throwing on gender-affirming outfits. ” — Non-binary account planner

For non-binary people especially, choosing how to present at work can be a challenge—and a “visual observation” from an HR rep would be nowhere near enough to ascertain the gender they would prefer to be counted as on the EEO-1, let alone their full identity.

“Dressing in a manner that is professional but makes me feel comfortable with how the world perceives me has become a bit of a chore,” the non-binary account planner said. “Often times, I feel as though I am either completely erasing myself by dressing in what people assume to be women’s clothes—or I am coming off sloppy by opting out of wearing makeup and throwing on gender-affirming outfits.”

Some companies, as Lyssa Test wrote for Namely, have tried to work around this issue by being up front with employees about what kind of gender-related information they need to collect and why—asking, for instance, for “gender, as required for EEOC and legal reporting purposes” or for “sex, for EEO purposes.”

By doing so, Test noted, companies can “remain compliant” but “still acknowledge their employee’s identities” within internal systems that list a range of gender non-conforming choices.

But until non-binary Americans receive federal-level recognition—enough, at least, for the EEOC to list more than two gender options—they will still be sorted into one box or the other in some form at work, whether they notice it happening or not.

In the meantime, Dumlao says, it’s up to companies to figure out how to prepare for a generation that is eschewing traditional understandings of gender in favor of a more expansive view—one greater than two.

“These are the people who are going to become our next workforce, who are going to become our future leaders,” they told The Daily Beast. “Companies and businesses that are not understanding that in the long-term are already behind.”