If you are transgender, determining which bathroom you are legally allowed to use in North Carolina is complicated. The answer depends on your birth certificate gender marker, which, in turn, depends on where you were born and whether or not you’ve had sex reassignment surgery (SRS).

But while litigation flies back and forth between the White House and the Tar Heel State over the now-notorious anti-LGBT law HB 2, a new lawsuit filed last week in the Eastern District of Pennsylvania could have significant implications not just for bathroom bills, but for transgender rights nationwide.

On May 13, the Philadelphia-based nonprofit Trans-Help filed a suit on behalf of two anonymous transgender plaintiffs, “John Doe” and “Jane Doe,” demanding that the Pennsylvania Division of Vital Records allow them to receive new birth certificates without having to undergo SRS.

The suit alleges that gender dysphoria, a psychiatric diagnosis in the DSM-5 that many transgender people receive, should be considered a “disability” under the Americans with Disabilities Act (ADA) and that, therefore, requiring SRS to issue a new birth certificate is a violation of the Equal Protection Clause.

“It will provide security and protection for trans people born in Pennsylvania who choose to change their birth certificate because the law will recognize them for who they really were born as—as who they really are,” attorney Julie Chovanes from Trans-Help told The Daily Beast of the suit’s possible consequences. “So it’s the right thing to do.”

Chavones is one of two attorneys representing the two Does. A spokesperson for the Pennsylvania Department of Health told The Daily Beast that they are reviewing the case but cannot comment on pending litigation as a matter of policy.

Like the majority of U.S. states, Pennsylvania requires SRS to issue a new birth certificate to a transgender person or to amend an existing one. A small but growing number of states, along with the District of Columbia, reissue birth certificates without requiring proof of SRS. A handful of states—Tennessee, Idaho, Kansas and, in some cases, Ohio—will not adjust birth certificates for trans people even if they have had SRS.

Among the many aspects of life that birth certificates affect—such as background checks and marriage license applications—they now determine where transgender people are allowed to pee in North Carolina.

Under HB 2, the state restricts public restroom use by birth certificate, which means that transgender people at the same stage of transition may be required to use different restrooms depending on their birthplace.

For instance, a transgender woman born in Washington can legally use a North Carolina ladies’ room without SRS provided she obtained a new birth certificate with a doctor’s note. A transgender woman born in Pennsylvania who has not had SRS could not legally accompany her.

Trans-Help’s suit applies inventive but not completely unprecedented legal reasoning to this vexing problem. Chovanes believes it is the first lawsuit of its kind to apply the ADA to birth certificate law.

The ADA, passed in 1990, explicitly excludes “transsexualism” and “gender identity disorders not resulting from physical impairments” from being treated as disabilities.

As Saranac Hale Spencer wrote for The Legal Intelligencer last year, these exclusions were originally intended to prevent the ADA from being used to protect “immorality.” The other exclusions, for example, are “pedophilia, exhibitionism, voyeurism.”

But medical consensus on transgender issues looks very different in 2016 than it did in 1990. Now, virtually every major medical professional association has issued statements supporting transgender health care. And last January, as Spencer reported for the Intelligencer, Kate Lynne Blatt became the first transgender person to explicitly challenge the constitutionality of the ADA’s transgender exclusions after being fired from the outdoor retailer Cabela’s. Her case is still pending.

At the core of the Trans-Help suit is the argument that gender dysphoria should qualify as a disability in spite of the stated exclusions in the ADA.

The ADA currently defines “disability” broadly as a “physical or mental impairment that substantially limits one or more of the major life activities of [an] individual.” As the ADA National Network notes, it is used as “a legal term rather than a medical one.”

Trans-Help’s suit alleges that because gender dysphoria causes “emotional and mental distress” and impacts life activities such as “interacting with others, reproducing, and social and occupational functioning,” it can be considered a disability—legally speaking, at least.

Following that logic, the suit goes on to claim that denying birth certificate gender changes to transgender people who have not had SRS would be unlawful discrimination against a subgroup, especially in light of the many obstacles to obtaining the surgery.

SRS is expensive, often excluded from private health insurance plans, and potentially risky for those with other medical conditions. Medical associations do affirm SRS as medically necessary for many people who experience gender dysphoria, but some transgender people find it unnecessary for their particular course of treatment.

Recognition of these obstacles has driven substantial federal-level change on transgender policy. Since 2010, transgender people have been able to update gender markers on their passports without surgery. In 2013, the Social Security Administration adopted a matching policy.

But now, under HB 2 and a nationwide wave of anti-transgender legislation, an updated birth certificate has become more important than ever for transgender people. It is, as Chovanes told The Daily Beast, “permission to pee” in at least one state.

Until new legislation is passed or court decisions get handed down, that document is determined by a messy and confusing patchwork of state laws that could take years to iron out.