What Is the National Firearms Act? NFA Explained (2026)

Last updated March 18th 2026

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Disclaimer: This article is for general informational purposes only and does not constitute legal advice. Firearms laws are complex and change frequently. Always consult a qualified attorney or your local ATF field office for guidance specific to your situation.

What Is the National Firearms Act?

The National Firearms Act (NFA) of 1934 is the federal law that regulates specific categories of firearms that Congress deemed “particularly dangerous” during the Prohibition era. It doesn’t ban these items outright. Instead, it imposes a registration requirement and a $200 tax on the manufacture, transfer, and possession of NFA-regulated weapons. If you’ve ever heard someone talk about a “tax stamp,” a “Form 4,” or “NFA items,” this is the law they’re referring to.

The NFA matters to every gun owner because it defines the line between what you can buy with a standard background check and what requires federal registration, months of waiting, and $200 in additional tax. Understanding the NFA is essential if you’re interested in short-barreled rifles, suppressors, or anything that falls outside the standard firearms market. It’s also the law that people reference (usually incorrectly) when they claim civilians “can’t own machine guns.” For how military and civilian firearms differ more broadly, see our military vs civilian firearms guide.

Why the NFA Was Created

The NFA was a direct response to the gang violence of the Prohibition era (1920-1933). Tommy guns, sawed-off shotguns, and other concealable automatic weapons were the tools of bootleggers, bank robbers, and organized crime. Names like Al Capone, John Dillinger, Bonnie and Clyde, and Pretty Boy Floyd made headlines with machine gun violence that terrified the public. Congress responded with the NFA, which didn’t ban these weapons but made them expensive and difficult to acquire through registration and taxation.

The original $200 tax stamp was deliberately set at a prohibitively high price for the era (roughly $4,500 in today’s dollars). The intent was to price these weapons out of the hands of criminals. Today, $200 is relatively modest, but the registration requirement, extensive background check, and months-long processing time remain significant barriers. For the full historical context, see our history of firearms guide and our Thompson submachine gun guide.

What the NFA Regulates: The Six Categories

The NFA defines six categories of regulated items. Possessing any of these without proper NFA registration is a federal felony.

1. Machine Guns

Any firearm that fires more than one round per trigger pull. This includes fully automatic weapons and burst-fire weapons. The legal definition covers the receiver (the part that houses the fire control mechanism), auto sears, and conversion kits. Civilian ownership of machine guns is further restricted by the Hughes Amendment (see below).

2. Short-Barreled Rifles (SBRs)

A rifle with a barrel length under 16 inches or an overall length under 26 inches. This is why civilian AR-15s have 16-inch barrels while military M4 carbines have 14.5-inch barrels. If you want a shorter barrel, you need an NFA tax stamp. The pistol brace controversy was entirely about this distinction: braces were designed to let AR-platform “pistols” sidestep SBR classification. See our AR pistol braces guide for more.

3. Short-Barreled Shotguns (SBSs)

A shotgun with a barrel under 18 inches or overall length under 26 inches. The same principle as SBRs: shorter barrels are more concealable, so they’re regulated. Standard pump shotguns and semi-auto shotguns have 18-inch or longer barrels to stay legal without NFA registration.

4. Suppressors (Silencers)

Any device designed to reduce the report (sound) of a firearm. Despite what Hollywood shows, suppressors don’t make guns silent. They reduce a gunshot from “instantly causes hearing damage” (160+ dB) to “loud but less damaging” (130-140 dB). That’s roughly equivalent to a jackhammer. Suppressors are legal in 42 states with an NFA tax stamp. They’re increasingly popular for hearing protection, especially for hunting and recreational shooting.

5. Destructive Devices

This covers two categories: explosive devices (grenades, mines, rockets) and firearms with a bore diameter over 0.50 inches (with exceptions for shotguns and sporting firearms). In practical terms, this means things like 40mm grenade launchers and large-bore anti-materiel rifles above .50 caliber are NFA items. Our .50 BMG rifles are not destructive devices because .50 BMG has a bore of exactly 0.50 inches, falling under the exemption threshold.

6. Any Other Weapon (AOW)

A catch-all category that includes disguised firearms (pen guns, cane guns), smooth-bore pistols, and certain other weapons that don’t fit neatly into the other categories. AOWs have a reduced tax stamp of $5 for transfers (vs $200 for other NFA items), making them the cheapest NFA category to acquire.

The Hughes Amendment: Why Machine Guns Cost $30,000+

The Firearm Owners Protection Act of 1986 (FOPA) included the Hughes Amendment, which banned the manufacture and registration of new machine guns for civilian ownership after May 19, 1986. This means no fully automatic weapon manufactured after that date can be legally owned by a private citizen, period.

Machine guns registered before the cutoff date (“pre-86” or “transferable” machine guns) can still be legally bought, sold, and possessed with an NFA tax stamp. But since there’s a fixed supply and growing demand, prices are astronomical. A transferable M16 costs $30,000 to $50,000+. A transferable Thompson submachine gun runs $25,000 to $40,000. A registered auto sear (which converts an AR-15 to full auto) is $30,000+. These are collector’s items at this point, not practical purchases.

For what civilians can actually buy in the full-auto-adjacent space, see our 3D printed guns guide (which covers the DIY/ghost gun debate) and our special forces guns you can buy guide for semi-auto civilian versions of military weapons.

How to Buy an NFA Item: The Process

Buying an NFA item is more complex and slower than a standard firearm purchase. Here’s how it works.

Individual Purchase

1. Find and purchase the item from a licensed dealer (Class 3 SOT / Special Occupational Taxpayer). The dealer holds the item until your paperwork clears.
2. Complete ATF Form 4 (Application for Tax Paid Transfer and Registration). This form includes your personal information, passport-style photos, and fingerprint cards.
3. Pay the $200 tax stamp ($5 for AOWs). This is a one-time tax per item, not an annual fee.
4. Notify your local Chief Law Enforcement Officer (CLEO). You must send a copy of the Form 4 to your local sheriff or police chief. This is notification only; they cannot deny the transfer.
5. Wait for ATF approval. Processing times vary but typically run 4 to 12 months as of 2026. E-Form 4 (electronic filing) has significantly reduced wait times compared to paper forms.
6. Pick up your item from the dealer after approval.

Trust or LLC Purchase

Many NFA buyers use a gun trust (a legal entity) rather than an individual purchase. A trust allows multiple “responsible persons” to legally possess the NFA items, which is useful for family members or shooting partners. It also simplifies estate planning. All responsible persons on the trust must submit photos and fingerprints with the Form 4. A gun trust typically costs $50 to $300 to set up through an attorney or online legal service.

State-Level Restrictions

The NFA is federal law, but individual states can impose additional restrictions. Some states ban certain NFA items entirely:

• Suppressors: Legal in 42 states. Banned in California, New York, New Jersey, Massachusetts, Hawaii, Illinois, Delaware, and Rhode Island.
• SBRs: Legal in most states but banned or restricted in several, including New York, New Jersey, and California.
• Machine guns: Legal to possess (pre-86 transferables) in most states but banned in several, including California, New York, and Illinois.

Always check your state’s specific laws before purchasing an NFA item. Our gun laws by state hub has guides for every state.

Related Guides

• Military vs Civilian Firearms
• Pistol Brace Rules: Latest News
• 7 Best AR Pistol Braces
• 3D Printed Guns Guide
• Special Forces Guns You Can Buy
• Thompson Submachine Gun Guide
• The History of Firearms
• Gun Laws by State
• 10 Best AR-15 Rifles
• 10 Best .50 BMG Rifles

The Bottom Line

The National Firearms Act has regulated machine guns, short-barreled weapons, suppressors, and destructive devices since 1934. The Hughes Amendment of 1986 closed the machine gun registry to new civilian entries, making pre-86 transferable machine guns rare and expensive collectors’ items. For everything else on the NFA list, the process is straightforward but slow: find a dealer, file your Form 4, pay $200, wait for approval, and pick up your item.

The NFA is one of the most consequential pieces of firearms legislation in American history, and understanding it is essential for any serious gun owner. Whether you’re looking at suppressors for hearing protection, SBRs for home defense, or just want to know where the legal lines are drawn, this is the law that draws them.

FAQ: National Firearms Act