Washington — A unanimous Supreme Court today ruled against imposing more limits on sexual-discrimination and sexual-harassment lawsuits.

Today’s decision overturns a ruling by the U.S. Court of Appeals for the First Circuit, in Fitzgerald v. Barnstable School Committee. The appeals court found that lawsuits filed under Title IX, the 1972 law that prohibits sex discrimination at institutions that receive federal funds, could not also include claims of civil-rights violations under a Civil War-era federal law, Section 1983, that enforces the equal-protection clause of the 14th Amendment to the Constitution.

But Justice Samuel A. Alito Jr., who wrote the opinion for all nine justices, said that the two statutes were not mutually exclusive because each offers different protections and penalties. Claims under Section 1983 can be filed against individuals, for example, while Title IX lawsuits can be filed only against institutions.

“Because Title IX’s protections are narrower in some respects and broader in others than those guaranteed under the equal-protection clause, the court cannot agree with the First Circuit that Congress saw Title IX as the sole means of correcting unconstitutional gender discrimination in schools,” Justice Alito wrote.

The original suit had been filed by the parents of a kindergarten student in Hyannis, Mass., who charged that a third-grader had repeatedly forced their daughter to expose herself to him and to other students on a school bus during a six-month period in the 2000-1 school year.

A federal district-court judge in Massachusetts ruled that the student had faced sexual harassment that was “severe and pervasive” but that the school had not violated Title IX because the harassment stopped after school officials found out about the misconduct. The judge also dismissed the parents’ claims, under the equal-protection clause, “that the school discriminated on the basis of sex in both the investigation and proposed remedy.” A three-judge panel of the appeals court upheld the lower court’s rulings.

Now that the U.S. Supreme Court has reversed the appeals court’s decision, the lower courts will still have to decide on the merits of the parents’ charges of constitutional violations under the equal-protection clause.

The American Association of University Professors had signed on to a friend-of-the-court brief in support of the plaintiffs, who wanted the Supreme Court to overturn the appeals-court decision. Other groups that supported the plaintiffs include the American Bar Association, the American Civil Liberties Union, and the National Women’s Law Center. —Eric Kelderman