Supreme Court Rules Federal Contractors Cannot Immediately Appeal Immunity Denials

The high court unanimously decided that government contractors cannot seek immediate appellate review of a district court's rejection of their derivative sovereign immunity claims.

Published on Mar. 5, 2026

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In a unanimous decision, the Supreme Court ruled that federal government contractors cannot seek immediate appellate review under the collateral-order doctrine when a district court denies their claim of derivative sovereign immunity. The Court reasoned that derivative sovereign immunity operates as a merits defense, not a form of immunity, and therefore does not qualify for the collateral-order exception that allows immediate appeals of immunity denials.

Why it matters

This ruling limits the ability of federal contractors to challenge adverse immunity decisions before final judgment. It means they must wait until the end of the case to appeal an erroneous denial of derivative sovereign immunity, potentially exposing them to lengthy litigation and liability in the meantime.

The details

The case involved a lawsuit against the GEO Group, a private prison operator that ran a detention facility on behalf of the federal government. Plaintiffs challenged certain GEO Group policies, and the company asserted derivative sovereign immunity, arguing the government authorized and directed it to carry out the challenged actions. The district court rejected GEO Group's immunity claim, and the company sought immediate appellate review, but the Tenth Circuit held it lacked jurisdiction for such an interlocutory appeal.

  • The Supreme Court issued its unanimous decision on March 5, 2026.

The players

GEO Group, Inc.

A private prison operator that ran a detention facility on behalf of the federal government.

Menocal

The plaintiffs who challenged certain GEO Group policies at the detention facility.

Supreme Court

The highest court in the United States, which issued the unanimous ruling in this case.

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What they’re saying

“The Court concluded that an assertion of derivative sovereign immunity is in reality a merits defense. After all, the Court reasoned, sovereign immunity protects even unlawful conduct. By contrast, a federal government contractor that successfully invokes derivative sovereign immunity is not liable precisely because it complied with the law. As a result, derivative sovereign immunity operates as a merits defense, not a form of immunity.”

— Justice Kagan, Supreme Court Justice (Marketscreener.com)

What’s next

The ruling means federal contractors like GEO Group must wait until the end of the case to appeal an erroneous denial of derivative sovereign immunity, potentially exposing them to lengthy litigation and liability in the meantime.

The takeaway

This Supreme Court decision narrows the ability of federal contractors to immediately challenge adverse immunity rulings, requiring them to wait until the end of the case to appeal. It represents a significant limitation on the collateral-order doctrine and will impact how these types of disputes play out in the courts going forward.