Since 2021, 24 states have banned gender-affirming care for transgender youth, prompting dozens of legal challenges by transgender youth, families and advocates.

This week, for the first time, the land’s highest court will hear a challenge to one state’s law — which could prompt a domino effect for the others.

On Dec. 4, the U.S. Supreme Court will hear oral arguments in U.S. v. Skrmetti as it prepares to weigh whether Tennessee’s ban on gender-affirming medical care for transgender youth is constitutional. Jonathan Skrmetti is Tennessee’s attorney general.

The decision, which may not come until the spring or summer, could have implications for the future of gender-affirming care bans nationwide and how the court will address future transgender discrimination cases.

Here’s what you need to know ahead of oral arguments.

The case’s facts

Several transgender youth, their parents and a doctor sued Tennessee over its March 2023 ban on gender-affirming medical care for transgender youth, arguing it violates the equal protection clause of the U.S. Constitution’s 14th Amendment.

Tennessee’s ban, similar to other laws, prohibits doctors from performing medical procedures “for the purpose of enabling a minor to identify with, or live as, a purported identity inconsistent with the minor’s sex,” as assigned at birth.

Gender-affirming medical care seeks to support transgender and nonbinary people’s gender identity. For the small population of transgender youth, this mainly involves support through social transition, puberty blockers and hormones as children become adolescents. Gender-affirming surgery is rarely performed on minors.

The Tennessee law bars using puberty blockers and hormone therapy as part of gender-affirming care. But those treatments are still available to treat other conditions, such as congenital defects or precocious puberty (when puberty happens too young).

A Tennessee District Court initially ruled in the plaintiffs’ favor and blocked the bill from becoming law. But the 6th Circuit Court of Appeals overturned the lower court’s ruling in September 2023 and let the ban take effect.

The U.S. Justice Department joined the families’ petition for the Supreme Court to consider the case, which it granted earlier this year.

What are the arguments?

The families challenging the ban argue the law discriminates based on sex and transgender status under the equal protection clause.

The law prohibits medications from being prescribed for gender transition, so transgender youth can’t access them, but cisgender youth can — as long as the medications are being used to affirm the youths’ sex assigned at birth.

The plaintiffs also argue that the law discriminates based on sex because it allows certain medications, such as testosterone or estrogen, to be prescribed to one sex but not the other. Basically, they say, people’s sex determines the medications they can be prescribed.

The Supreme Court used similar logic in the majority opinion in Bostock v. Clayton County, Georgia, which found in 2020 that firing an employee for being transgender was sex discrimination under Title VII of the Civil Rights Act.

In its legal brief, Tennessee said its law is not discriminatory because it regulates a specific medical procedure for a specific purpose. The state said it does not classify based on sex or transgender status, because the law applies equally to both sexes. The power to regulate safe medical care falls within the state’s authority, state lawyers argued in their briefs.

“They’re arguing they want to ban this form of treatment for this diagnosis,” said Elana Redfield, federal policy director at the Williams Institute, an LGBTQ+ policy research institute at the UCLA School of Law. “But what the plaintiffs are arguing, not explicitly, but in summary, is that this diagnosis is a proxy for a class of person.”

How does ‘scrutiny’ come into play?

Some laws require classifying people into groups. A legal drinking age for example, treats minors and adults differently under the law. But historically, some laws that classify people based on a characteristic have been used to treat certain racial groups or sexes unfairly.

As a result, the federal courts have developed a method — referred to as “levels of scrutiny” — to determine how a law classifies people and whether the government has a good enough reason to do so.

There are three different levels of scrutiny depending on who or what characteristic is at issue: rational-basis, intermediate, and strict. Tennessee argues it needs to pass only the lowest level of scrutiny known as rational-basis, which means the law need be based only on a “legitimate government interest” and be rationally constructed to be constitutional.

But, the court could decide the law merits intermediate scrutiny, a higher scrutiny level triggered when laws classify people based on sex. Passing intermediate scrutiny is harder. A law must serve an “important government interest” and be more narrowly written to avoid unnecessary discrimination.

“The level of scrutiny the court gives to the case really affects how hard the government has to work to justify it,” Redfield said. The higher the scrutiny, the more likely a law will be deemed unconstitutional.

Because this case deals with the 14th Amendment’s equal protection clause, justices will need to decide what level of legal scrutiny Tennessee’s law merits.

Deciding a law’s level of scrutiny and whether it passes that level are two distinct legal questions. The court could rule just on the scrutiny level and leave it to lower courts to decide whether the trans health ban passes, or it could rule on both questions.

What are some possible outcomes?

Experts and advocates see a range of possible outcomes depending on what scrutiny level the justices assign the law and whether it clears that level.

• What the plaintiffs want: The court could rule that the law discriminates based on sex or gender identity and merits intermediate scrutiny. The justices could then pass the case back to the lower courts to determine whether it passes that level of scrutiny, or they could determine it themselves. Whether the court’s decision will apply to future cases will hinge on how broadly the decision is written.
• What the defendants want: The court could affirm the 6th Circuit Court’s opinion that the law does not discriminate based on sex or gender identity and merits only rational-basis review, finding that it passes that test.
• Two less likely outcomes: The court could agree that the law merits only rational-basis review but find that it fails to pass that test. That’s what happened in Romer v. Evans, a 1996 case in which the court overturned a Colorado amendment prohibiting municipalities from adding LGBTQ+ protections to local laws. Although the court found that the amendment qualified for rational-basis review, it said the amendment was not a legitimate government interest because the state Legislature was motivated by animus against LGBTQ+ people.

The court could go beyond the case’s specifics and broadly declare that discrimination against transgender people does not count as sex discrimination under the 14th Amendment. This would hinder future cases that try to argue transgender discrimination under the Constitution.

A Supreme Court ruling in favor of trans youth could strengthen other transgender rights legal challenges relating to sports and bathroom bans.

But simply deciding the law merits heightened scrutiny does not mean it will be overturned.

If the court rules in Tennessee’s favor, it would make challenging future laws harder, but not impossible, legal experts said.

This fact check was originally published by PolitiFact, which is part of the Poynter Institute. See the sources for this fact check here.