A short excerpt from the long Justice Department Office of Legal Counsel Aug. 12 memo to the Attorney General:

You have asked whether 18 U.S.C. § 930(a) … is best read to impose criminal penalties on an otherwise law-abiding individual who carries weapons into a post office for the purpose of self-defense. We would have significant constitutional concerns if Congress had created such a blanket ban on the lawful carrying of constitutionally protected arms into a building frequented by the public since the Founding. But we ultimately need not reach that issue here, as Congress has exempted the "lawful carrying" of firearms or other dangerous weapons "incident to hunting or other lawful purposes." Because carrying arms for self-defense when entering a building held open to the public is a paradigmatic "lawful purpose[]," that exception permits the lawful carrying of constitutionally protected firearms in post office….

[S]ection 930(d)(3) provides that section 930(a)'s bar against carrying firearms and dangerous weaponry does not apply to "the lawful carrying of firearms or other dangerous weapons in a Federal facility incident to hunting or other lawful purposes." 18 U.S.C. § 930(d)(3). To fall within this exception with respect to firearms, an individual must satisfy two criteria: (1) the carrying of their firearm must be "lawful"; and (2) the carrying must be "incident to" a "lawful purpose[]," such as "hunting."

The first requirement is relatively straightforward. It excludes, for example, a person who is not legally allowed to carry a gun anywhere…. Under federal law, this exemption would not cover, for example, a person who has been convicted of a felony or a misdemeanor crime of domestic violence, a person who has been committed to a mental institution, or a person who is in the United States illegally. It may also exclude an individual who is forbidden from carrying a firearm in the relevant state because he is not licensed—so long as the licensing regime itself is not constitutionally infirm…

The second requirement is less clear but is best read to cover an individual entering a post office that is open to the public while lawfully carrying a firearm for self-defense. "Incident," used as an adjective, means "occurring or likely to occur esp[ecially] as a minor consequence or accompaniment." In the legal context, "incident" means "depends upon, appertains to, or follows another."

But section 930(d)(3) does not specify whether the "lawful purpose" to which the carrying of a firearm must accompany is the purpose for entering a federal building or the purpose for carrying the firearm. Read in conjunction with background principles of law, we think the better view is that an individual needs both a lawful purpose to be in a federal facility and a lawful purpose to carry a firearm in order for the individual to qualify for the exception in section 930(d)(3), but not necessarily that the two must be related. So understood, an otherwise law-abiding citizen who carries a constitutionally protected firearm into a post office that is generally open to the public would fall within the scope of that exception….

Carrying arms for self-defense when entering a building held open to the public is a paradigmatic lawful purpose…. Unless the property owner has clearly closed the property to firearms being carried for self-defense, such carrying is presumptively lawful. Yet far from closing post offices to firearms, Congress expressly permitted the carrying of firearms incident to any lawful purpose.

Interpreting "lawful purpose" in section 930 to include self-defense in a building held open to the public is also consistent with other rules of statutory construction. For example, take the semantic canons of noscitur a sociis and ejusdem generis. In the Second Amendment context, hunting is often paired with self-defense as an archetypal lawful purpose. See, e.g., 15 U.S.C. § 7901(b)(2) (outlining Congress's purpose of "preserv[ing] a citizen's access to a supply of firearms and ammunition for all lawful purposes, including hunting, self-defense, collecting, and competitive or recreational shooting"). So if an individual who is not legally disabled from possessing a firearm enters a post office that is held open to the public while properly carrying a firearm for self-defense, section 930(d)(3) applies to exempt them from section 930(a)'s carrying ban, as the individual is "lawful[ly] carrying" a firearm "incident to" a "lawful purpose[]." …

This interpretation is further supported by the canon of constitutional avoidance, which "imposes"—at minimum—a "'clarity tax' on Congress" when it legislates in ways that raise constitutional doubts…. Because [§ 930(a)] falls within the plain text of the Second Amendment, the restriction is "presumptively unconstitutional." As applied to post offices that are generally open to the public, we have grave doubts that the government could carry its burden to overcome that presumption by demonstrating the restriction "is consistent with the Nation's historical tradition of firearm regulation." That would be a high hurdle because, for nearly two centuries, there was no ""historical tradition of firearm regulation" in post offices. Moreover, it is unlikely that the government would be able to overcome that hurdle by reference to the "sensitive places" doctrine because ordinary post offices appear to bear no legally significant resemblance to the ""legislative assemblies, polling places, and courthouses" where the Court has accepted that the government may presumptively restrict firearms….

The opinion was written by Lanora C. Pettit, Principal Deputy Assistant Attorney General.

UPDATE 8/25/26, 1:45 pm: Check out also the recently posted The Post Office Was the General Store: Sensitive Functions, Absent Premises, and the Post-Office Carry Ban, by Jonathan S. Goldstein. The Abstract:

Modern law begins from an inverted premise: the armed citizen in the post office is treated as the problem, and the gun-free federal building as the timeless baseline. The history runs the other way.

It is not that the post office sat inside a store and therefore could not be sensitive. At the founding, nearly everything sat inside a store or a tavern: the Congress of the Confederation sat in the French Arms Tavern, the War Office in Fraunces Tavern, and the Supreme Court above an open-air market. The building never carried the rule. What carried the rule was the function. The founding generation designated sensitive occasions rather than sensitive addresses — Delaware in 1776 disarmed "the said elections," and Virginia in 1786 disarmed the man who came before "the justices of any court .. . doing their office" — and no founding-era designation of the mail has been located. There was nothing to designate.

Nor is the omission explained away by the government's ownership of the modern building. The statute the government enforces does not turn on ownership: § 930 reaches a building "owned or leased" by the United States, and when Congress described the archetypal sensitive place in the same section it named a courtroom, a jury room and the chambers of a judge, with no ownership term at all. Title is not the axis. Function is — and the function performed across a post-office counter is retail.

The Post Office Act of 1792 required only that "every deputy postmaster shall keep an office," and the Act of 1825 that "every postmaster" do so — a duty that ran in each case to the man and not to the room; there would be no federal Supervising Architect until 1852, and no division of the Department devoted to post-office quarters until the second decade of the twentieth century; and what that record establishes is not that the sovereign lacked a deed, but what a citizen crossing the threshold was walking into. He was walking into a store.

After New York State Rifle & Pistol Ass'n v. Bruen, the government bears the burden of producing a founding-era tradition that would justify disarming the law-abiding citizen at the post office. It must therefore produce a tradition of disarming people at a place that did what the post office did. This Article marshals the affirmative record — the Postal Service's own institutional history, federal historic-site nominations, the surviving account books of merchant-postmasters, and the practice of a postal system that itself carried, mailed, and guarded arms — and shows that the post office is among the poorest available candidates for a founding-era "sensitive place." The burden is the government's, and on this record it cannot carry it.