By Ariane de Vogue and Devan Cole, CNN

(CNN) -- The Supreme Court declined on Monday to take up a case from parents in Oregon who challenged a public school's policy allowing a transgender student to use the bathroom that corresponded with his gender identity.

The petition was considered a long shot because of several complicated threshold issues, including the fact that the policy had been put in place five years ago for one student -- referred to as "student A" -- who has since graduated from the high school located in Dallas, Oregon. At issue was an individualized plan drawn up specifically for "student A."

In declining to take up the petition, the justices left in place an appeals court decision earlier this year that held that the school's policy intended to "avoid discrimination and ensure the safety and well-being of transgender students."

"A policy that allows transgender students to use school bathroom and locker facilities that match their self-identified gender in the same manner that cisgender students utilize those facilities does not infringe Fourteenth Amendment privacy or parental rights or First Amendment free exercise rights, nor does it create actionable sex harassment under Title IX," Judge Atsushi Wallace Tashima wrote for the appeals court.

The Supreme Court's action Monday was taken without comment or noted dissent.

The American Civil Liberties Union cheered the court's move on Monday, saying the justices' message was that "transgender youth are not a threat to other students."

"The decision not to take this case is an important and powerful message to trans and non-binary youth that they deserve to share space with and enjoy the benefits of school alongside their non-transgender peers," Chase Strangio, the deputy director for trans justice with the ACLU's LGBT and HIV Project, said in a statement.

Despite Monday's order, the issue isn't likely to go away soon. Other lower courts have addressed a related question brought by lawyers for transgender students concerning whether Title IX or the Constitution requires schools to allow transgender students to have equal access to bathrooms consistent with their gender identity. A case on that issue is expected to reach the court early next year.

The transgender bathroom debate has long been a flashpoint for the court. Supporters of LGBTQ rights fear that the Supreme Court's newly solidified 6-3 conservative majority could prove to be hostile toward policies in favor of transgender students.

In late August, a federal appeals court handed a win to a transgender former student in a years-long fight over restroom policies, ruling that policies segregating transgender students from their peers are unconstitutional and violate federal law prohibiting sex discrimination in education. That decision relied in part on the Supreme Court's ruling earlier this year in favor of LGBT workers.