Businesses across the United States are grappling with what a return to the office may look like post-pandemic, but their employees may be grappling with how they may look when they go back to work. What does an employer do if one or more of its employees has transitioned during the virtual work period? What questions can you legally ask the employee? Can you demand proof?

What do you do if your office reopens and the employee you knew pre-pandemic as “Frank” reintroduces herself as “Francine”?

Last year in Bostock v. Clayton County, Georgia, the Supreme Court held that discrimination based on an employee’s transgender status is sex discrimination in violation of Title VII. As the Court noted, when an employer discriminates against a transgender individual, it “intentionally penalizes a person identified as male at birth for traits or actions that it tolerates in an employee identified as female at birth.” Last month, the EEOC celebrated the anniversary of the Bostock decision by issuing new resources regarding sexual orientation and gender identity in the workplace.

Thus, an employer has a legal obligation to ensure that it isn’t discriminating against a transgender employee like Francine. Francine cannot be fired from her job because her employer has now learned of her transgender status, or because she now presents as female. She also cannot be forced to wear a man’s uniform or use a certain restroom, for example. Francine’s employer also has an obligation to ensure that her coworkers are not creating a hostile work environment for her based on her gender identity.

Relatedly, the employer also has an obligation to ensure that managers and coworkers use Francine’s preferred pronouns. The EEOC recognizes that a persistent failure to use those preferred pronouns could constitute actionable harassment.

What if Francine hasn’t changed anything about her appearance, but has informed you that she has changed her name and is in fact female?

Legally, there is no single way to define a person’s gender, and there is no one point in time when a person transitions from one gender to another. In addition, the laws surrounding legal and medical transitions vary across jurisdictions. Given these complexities, any employer subjects itself to legal exposure if it links its recognition of a person’s gender to any particular transition milestone.

At this time, few courts have weighed in on when exactly a person is drawn under the umbrella of Title VII’s protections for transgender employees. State legislatures—some of which have prohibited discrimination based on gender identity for a number of years—have themselves taken varied approaches.

For example, anti-discrimination statutes in states like Maryland, Massachusetts, Delaware, and New Hampshire contemplate that gender identity may be demonstrated by unspecified evidence that the proffered gender is a sincerely held aspect of that individual’s core identity. Massachusetts and New Hampshire, along with other states like Connecticut and Utah, contemplate that an employee may demonstrate gender identity by medical evidence as well, although medical evidence is not the sole means of doing so. While other state statutes remain silent on the issue, California’s transgender protections prohibit an employer from asking for any kind of “proof” of gender identity as a condition of employment; they also cover individuals who are in the process of transitioning, have already transitioned, or are perceived to be transitioning. Given state law variations—and a general lack of guidance as to the concrete means by which to assess transition—the best practice will usually be for an employer to accept the employee’s stated gender identity. The employer should then work with the employee to make the necessary changes to personnel records, identification cards, and email addresses, among other things.

Does it matter if you think Francine is asserting a particular gender identity for an improper purpose?

Several states’ laws—like those in Connecticut and New Hampshire—note that transgender status is not protected if it is asserted for an “improper purpose.” These laws do not make clear what would constitute an improper purpose.

Employers should think carefully about this line of inquiry, given the very little legal guidance that exists at this time for employers who may question whether an employee’s gender identity is sincerely held. Courts and legislatures may one day adopt a standard akin to the one applied to requests for religious accommodations by an employee, which allows for limited inquiries into an employees’ religious beliefs to determine sincerity. In denying a requested religious accommodation, an employer may consider, among other factors, whether an employee behaves inconsistently with the professed belief and whether the timing of the accommodation request renders it suspect. Similar factors could one day be applied if an employer disputes the sincerity of an employee’s claimed gender identity.

As a practical matter, however, most employers do not inquire into the sincerity of their employees’ religious beliefs; the same should likely be true if employees notify their employers that they are transgender. Requesting unnecessary or excessive “proof”—of either an employee’s religious belief or transgender status—opens the employer up to claims of retaliation or harassment.