The rule of the last antecedent and the series qualifier canon are two grammatical tools courts use to decide what a trailing modifier in a statute or contract actually reaches. The last antecedent rule attaches the modifier only to the nearest item before it. The series qualifier canon spreads it across every item in the list. They often point to opposite readings of the same sentence, and no fixed hierarchy tells a court which one wins.
What the Last Antecedent Rule Says
A limiting phrase or clause modifies only the word or phrase immediately before it, not earlier items in a list.1Legal Information Institute. Rule of the Last Antecedent It is a proximity default: the modifier grabs the closest noun and stops. If a contract refers to “institutions, businesses, and licensed nonprofit organizations operating within the state,” the rule treats “operating within the state” as describing only the nonprofit organizations. The institutions and businesses carry no geographic limitation.
The Supreme Court gave the rule its most-cited modern treatment in Barnhart v. Thomas, 540 U.S. 20 (2003). The Social Security statute at issue listed types of work a disability claimant must be unable to perform, ending with “any other kind of substantial gainful work which exists in the national economy.” The Court held that “which exists in the national economy” modified only the final category, not every type of work listed earlier. Justice Scalia, writing for a unanimous Court, called the application “quite sensible.”2Legal Information Institute. Barnhart v Thomas
The rule resurfaced with higher stakes in Lockhart v. United States, 577 U.S. ___ (2016). A federal statute imposed a mandatory minimum for possessing child pornography if the defendant had a prior conviction under state law “relating to aggravated sexual abuse, sexual abuse, or abusive sexual conduct involving a minor or ward.” The majority applied the last antecedent rule and held that “involving a minor or ward” attached only to “abusive sexual conduct,” meaning a prior conviction for sexual abuse of an adult still triggered the enhancement.3Legal Information Institute. Lockhart v United States That reading added years to the defendant’s sentence.
What the Series Qualifier Canon Says
The series qualifier canon pushes the other way. When a modifier follows a straightforward, parallel list of nouns or verbs, it applies to every item in the series, not just the last one.4The Scribes Journal of Legal Writing. Dont Forget Me! Structure as a Part of Plain Language If someone says “bring your shirts, pants, and jackets that are waterproof,” most listeners understand all three items need to be waterproof.
The Supreme Court recognized this reading as early as 1920 in Porto Rico Railway, Light & Power Co. v. Mor, 253 U.S. 345, stating that “when several words are followed by a clause which is applicable as much to the first and other words as to the last, the natural construction of the language demands that the clause be read as applicable to all.”5Justia Law. Porto Rico Ry Light and Power Co v Mor, 253 US 345 (1920) That language has been quoted in dozens of later opinions when a court wants to throw a trailing modifier back across an entire list.
More recently, the Court used the canon in Facebook, Inc. v. Duguid (2021). The Telephone Consumer Protection Act defined an autodialer as equipment with the capacity “to store or produce telephone numbers to be called, using a random or sequential number generator.” The Court read “using a random or sequential number generator” as modifying both “store” and “produce,” narrowing the statutory definition.6Legal Information Institute. Facebook Inc v Duguid
When the Two Canons Collide
The two canons often point to opposite readings of the same text. Judge Richard Posner of the Seventh Circuit put it bluntly: the series qualifier canon “contradicts” the last antecedent canon, and “we don’t know how to choose between them.” There is no established hierarchy for picking one when both plausibly apply.
Lockhart is the clearest Supreme Court illustration. The six-justice majority applied the last antecedent rule. Justice Kagan’s dissent argued that the series qualifier canon was the better fit, saying that reading the modifier as reaching all three listed crimes “reflects the completely ordinary way that people speak and listen, write and read.”3Legal Information Institute. Lockhart v United States If someone said “I’m looking for people who’ve committed robbery, assault, or fraud involving a firearm,” most listeners would hear the firearm requirement as applying to all three crimes.
Neither canon is a trump card. Courts tend to reach for the last antecedent rule first, but the series qualifier canon wins when the listed items form a natural parallel category and the modifier logically applies to all of them. Context and statutory purpose do more work than either rule standing alone.
How Punctuation Changes the Result
A single comma can shift which canon controls. When a comma appears after the last item in a list but before the modifying phrase, courts generally treat that as a signal that the modifier applies to every item, favoring the series qualifier reading.7Judicature. The Doctrine of the Last Antecedent, the Example in Barnhart, and Why Both Are Weak Without that comma, the last antecedent rule typically governs.
The Second Circuit applied this distinction in AIG v. Bank of America, 712 F.3d 775 (2d Cir. 2013). The Edge Act listed three types of offshore banking transactions, then a comma, then a modifier about whether the transaction was done directly or through an agency. Because a comma separated the last list item from the modifier, the court held the modifier applied to all three transaction types. The court noted explicitly that without the comma, the result would have followed Barnhart and attached the modifier only to the final item.8Justia Law. AIG v Bank of America, No 12-1640 (2d Cir 2013)
Punctuation is not always dispositive. The Supreme Court cautioned in U.S. National Bank of Oregon v. Independent Insurance Agents, 508 U.S. 439 (1993), that while a statute’s meaning will “typically heed the commands of its punctuation,” a reading based only on punctuation is “necessarily incomplete.” Texas courts go further, holding that “the words, not the punctuation, are the controlling guide in construing a contract,” and that clear words override contrary punctuation. A comma helps, but it is not a guarantee.
When Courts Set Both Canons Aside
Both canons are rules of thumb, not mandates. Judges reserve authority to look past grammar when the broader purpose of a statute demands it, and three doctrines in particular can displace a canon-driven reading.
Absurdity
When a grammatical reading leads somewhere no reasonable legislature could have intended, courts invoke the absurdity doctrine. The bar is high. A result is not absurd merely because it seems harsh or produces policy outcomes a judge dislikes. The interpretation must be so unreasonable that attributing it to the legislature would undermine the statute’s own stated goals.
The Rule of Lenity
Criminal law adds another layer. When a penal statute remains genuinely ambiguous after the usual interpretive tools, the rule of lenity requires courts to adopt the reading most favorable to the defendant. Chief Justice Marshall explained in 1820 that “the power of punishment is vested in the legislative, not in the judicial department,” and courts should not extend a criminal penalty beyond what the statutory language plainly imposes. In United States v. Santos (2008), a Supreme Court plurality applied lenity to read “proceeds” in a money laundering statute as net profits rather than gross receipts.9EveryCRSReport.com. Statutory Construction in the Criminal Law Context – Selected Principles and Examples Where the two canons point to different readings of a criminal statute and neither clearly prevails, lenity can break the tie.
Scrivener’s Error
Occasionally a statute’s punctuation or phrasing is a drafting mistake. Courts can correct scrivener’s errors, but only when the mistake is “absolutely clear.” A misplaced comma that creates genuine ambiguity is usually not enough. The doctrine is reserved for typos and clerical blunders where the intended text is beyond dispute.10Northwestern University Law Review. The Scriveners Error
Drafting So Neither Canon Matters
The surest way to keep these canons from controlling your meaning is to draft so clearly that neither is needed. A few structural habits prevent most trailing-modifier disputes.
- Repeat the modifier with each item. Instead of “temporary and part-time employees covered by the agreement,” write “temporary employees covered by the agreement and part-time employees covered by the agreement.” Repetitive, but unambiguous.
- Use numbered lists. Breaking a series into enumerated subparts eliminates debate about where a modifier attaches. In “(1) internal documents, (2) external reports, and (3) digital files belonging to the company,” “belonging to the company” clearly modifies only item three.
- Move the modifier to the front. “Company-owned internal documents, external reports, and digital files” applies the ownership requirement to all three items without relying on any canon.
- Use explicit scope language. Phrases like “each of the foregoing” or “all of which must be” remove any doubt about whether a modifier reaches the full list.
The U.S. House of Representatives’ Legislative Counsel manual advises drafters to use a comma after the last list element when a modifier is meant to reach every item, and to repeat the conjunction or break the provision into a formatted list when the modifier is meant to reach only the final item. Its overarching guidance: when in doubt, be specific rather than relying on punctuation conventions that courts may or may not follow.11Office of the Legislative Counsel, U.S. House of Representatives. House Legislative Counsels Manual on Drafting Style
Avoid “and/or.” It compounds modifier ambiguity by muddying whether items in a list are alternatives or cumulative requirements. Using “or” alone, supplemented by “and may do both” when needed, is cleaner and far less likely to trigger litigation over scope.