The Supreme Court voted 7–2 on March 26 to uphold the Biden administration’s rule regulating so-called ghost guns that can be assembled at home.

In October 2023, the Supreme Court reinstated the rule, which lower courts had blocked.

“Ghost gun” is a pejorative term used by gun control advocates to describe a homemade firearm that lacks a serial number and therefore can’t be tracked by law enforcement.

Although some states regulate homemade guns, gun control groups have been trying for years to ban or regulate homemade guns at the federal level but have failed to persuade the U.S. Congress to act.

Then-President Joe Biden defended the rule, claiming that privately made guns, which are often made with gun kits, are the “weapons of choice for many criminals.”

The government’s “frame or receiver” rule dates to April 2022. It requires individuals who assemble homemade firearms to add serial numbers to them. The rule also mandates background checks for consumers who buy gun-assembly kits from dealers.

Pieces of guns that are shipped are nonetheless guns subject to existing laws, the government argues.