How Are States Responding to VanDerStok?

On June 25, the Michigan Senate passed a bill banning the manufacture, assembly, and possession of firearms without valid serial numbers, commonly known as “ghost guns.” The bill also prohibits “ghost gun precursors,” which are frames or receivers, whether finished or unfinished. The proposed legislation in Michigan is part of a broader effort by state and local governments to address problems posed by ghost guns in light of uncertainty surrounding regulation at the federal level.

Many ghost guns are made from weapon parts kits that contain component parts of a firearm. As the Supreme Court recently noted in Bondi v. VanDerStok, which upheld the federal government’s ability to regulate such kits as “firearms” under the Gun Control Act, “companies are able to make and sell weapon parts kits that individuals can assemble into functional firearms in their own homes.” With tools and instructions from publicly accessible YouTube videos, an individual can easily convert the components in a weapon parts kit into a functioning ghost gun in as little as 21 minutes. However, kits vary in the time, tools, and expertise required. 

Ghost guns can also be built using 3D printers and blueprints found online, such as the firearm used in the killing of the UnitedHealthcare CEO. 3D-printed ghost guns generally fall into three categories: (1) most commonly, 3D-printing is used to create a frame or receiver to complete a weapon parts kit; (2) 3D-printed materials and readily available common parts can be used to make a functioning ghost gun; and (3) in some instances, it is possible to fully 3D-print a working firearm. 

Ghost guns pose unique challenges to law enforcement. Ghost guns and their precursors lack serial numbers, making them difficult for law enforcement to trace. Prior to 2022, federal law permitted manufacturers to sell weapons parts kits without obtaining a federal license, keeping sales records, or performing background checks. Ghost guns are thus particularly useful for criminal activity, with law enforcement recovering more than 92,000 ghost guns from crime scenes between 2017 and 2023. 

In 2022, the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) under President Biden issued a rule designed to subject gun-assembly kits and firearm component parts to the regulatory framework set forth in the Gun Control Act (GCA) of 1968. The rule interpreted the language “any weapon (including a starter gun) which will or is designed to or may readily be converted to expel a projectile by the action of an explosive” to include weapon parts kits. Another provision of the rule expanded the definition of “frame or receiver” to include those that are “partially complete, disassembled, or nonfunction[ing]” and can readily be converted into a functioning frame or receiver.

In March 2025, the Supreme Court upheld ATF’s rule in Bondi v. VanDerStok. Writing for the majority, Justice Gorsuch held that “[t]he GCA . . . permits ATF to regulate[] some weapon parts kits and unfinished frames or receivers.” The majority reasoned that ATF’s rule was not facially unconstitutional under the GCA because at least some weapon parts kits are “weapon[s] . . . [which] may readily be converted to expel a projectile by the action of an explosive.” Justice Gorsuch cautioned that weapon parts kits requiring “more time, expertise, or specialized tools” to create a working firearm might not fit within the GCA’s definition. Justices Thomas and Alito dissented.

Even though the Court upheld the rule in March, the future of federal regulation of ghost guns remains uncertain. VanDerStok determined that the ATF rule was a permissible regulation, but the Trump administration might still choose to repeal the rule or substantially scale back enforcement. In February, President Trump ordered the Attorney General to review all rules promulgated by ATF during former President Biden’s term for consistency with the Second Amendment and gun rights. 

A new legal challenge also threatens the ATF rule. In June, the Plaintiffs in VanDerStok moved for a preliminary injunction on the grounds that the rule violates the Fifth Amendment’s Due Process Clause and the Second Amendment. Until the Supreme Court decision, the Plaintiffs had not challenged the rule on Second Amendment grounds. However, the Plaintiffs suggested raising a Second Amendment claim if their administrative law challenge failed. The Plaintiffs argue that the ATF rule infringes the Second Amendment’s right to “keep . . . Arms,” which includes the right to acquire and make arms. They claim that the United States has a historical tradition of gunsmithing and self-manufacture of firearms for personal use, which was left largely unregulated historically. In response, the Defendants contend that the ATF rule is consistent with the nation’s historical tradition of “ensur[ing] only law-abiding citizens acquire firearms” through licensing, recordkeeping, and serialization requirements. 

Previous attempts at federal legislation addressing ghost guns have been unsuccessful. In 2023, the Ghost Guns and Untraceable Firearms Act failed to make it out of committee. Similar legislation specifically targeting 3D-printed ghost guns was introduced in the House and Senate in June 2025. The bill would prohibit distributing design blueprints for 3D-printed firearms online.

The narrowness of the VanDerStok majority opinion leave an open question in ghost gun regulation. The majority reasoned that some gun-assembly kits and component parts may be so readily convertible that they can permissibly be regulated by ATF as “firearms.” However, other kits or collections of gun parts that are “incomplete or cumbersome to assemble” likely cannot be characterized as firearms and may not be regulated under existing statutes. The uncertainty surrounding where the line is drawn could prompt state and local governments to address the issue, such as by drafting laws that apply broadly to all kits—even those that require more time and effort to assemble into a working gun.

Fifteen states—California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maryland, Massachusetts, Nevada, New Jersey, New York, Oregon, Rhode Island, Vermont, and Washington—and the District of Columbia already regulate ghost guns in some form. At a minimum, these laws require serial numbers on firearms and component parts. Most also require background checks for component parts, and some include explicit bans on possessing gun assembly kits and/or 3D-printed firearms.  

With uncertainty surrounding the future of federal ghost gun regulation, state and local governments are preparing to play a more active role. In addition to the pending Michigan legislation described above, other examples include:

• The Maine legislature passed a bill requiring serial numbers on firearms and unfinished frames or receivers, but the state’s Governor will hold the bill until the legislature returns next year.
• After the Pennsylvania Senate failed to pass a bill regulating ghost guns that the House approved, several local governments in Pennsylvania, including the City of Philadelphia, passed local ordinances prohibiting ghost guns. The Pennsylvania Supreme Court agreed to hear a challenge arguing that Pennsylvania’s state firearm preemption law precludes the Philadelphia ordinance.
• In March, North Carolina legislators introduced a bill that would ban ghost guns and other undetectable firearms. The bill has not moved since its introduction.
• In May, the Virginia Governor vetoed a bill passed by the state House and Senate prohibiting ghost guns. However, an older state law bans undetectable plastic firearms, which would include some 3D-printed ghost guns. 

If the Trump administration repeals the ghost-gun rule or scales back enforcement, or if constitutional challenges to the rule are successful, certain state and local governments will likely step in to fill the regulatory void with statutes specifically designed to combat the proliferation of ghost guns. 

Considering the ongoing VanDerStok litigation, these state ghost gun laws could soon face similar challenges on Second Amendment grounds. Unlike the ATF rule, which regulates ghost guns under existing law, state regulations on ghost guns result from newly enacted statutes. Since there is no corollary to a federal APA challenge that could be raised, state ghost gun regulations are on solid footing as a statutory matter and the constitutional challenge is the biggest roadblock. However, recent litigation in New York, Colorado, and Oregon suggests that these constitutional challenges are unlikely to succeed. For example, a 3D-printed gun without a serial number is likely not commonly used for lawful purposes and would, thus, not be protected by the Second Amendment.