What the Armed Career Criminal Act (§ 924(e)) does
The Armed Career Criminal Act, usually called the ACCA, is a federal sentencing law found at 18 U.S.C. § 924(e). It is not a charge of its own. No one is indicted for violating the ACCA. Instead, it waits behind a firearm charge under 18 U.S.C. § 922(g), most often felon in possession of a firearm, and raises the punishment when the person being sentenced has a particular kind of criminal record.
The core of the law is one sentence. It says that, for a person who violates the felon-in-possession law and "has three previous convictions by any court referred to in section 922(g)(1) of this title for a violent felony or a serious drug offense, or both, committed on occasions different from one another," that person "shall be fined under this title and imprisoned not less than fifteen years." The same sentence adds that "the court shall not suspend the sentence of, or grant a probationary sentence to, such person with respect to the conviction under section 922(g)."
Three parts of that sentence do the real work: the underlying gun conviction, the three earlier convictions, and the requirement that those earlier crimes happened on different occasions. Each one is explained below. This page sits within our overview of Federal Firearms Charges, and the underlying gun charge is described in detail on our felon in possession page.
The underlying charge: felon in possession under § 922(g)
The ACCA applies only to a convicted section 922(g) offender, as the statute opens with the words "(e)(1) In the case of a person who violates section 922(g) of this title". Section 922(g) makes it unlawful for certain listed people, including any person "who has been convicted in any court of, a crime punishable by imprisonment for a term exceeding one year," to do any of the following: "to ship or transport in interstate or foreign commerce, or possess in or affecting commerce, any firearm or ammunition; or to receive any firearm or ammunition which has been shipped or transported in interstate or foreign commerce."
In plain words, the government must prove three things for the gun charge itself. First, that the person falls into one of the barred groups, most often because of an earlier conviction carrying more than a year in prison. Second, that the person shipped, transported, possessed, or received a firearm or ammunition. Third, the commerce connection, meaning the gun or ammunition traveled across state or national lines or otherwise touched interstate commerce. The penalty section adds a knowledge requirement: "Whoever knowingly violates subsection (d) or (g) of section 922 shall be fined under this title, imprisoned for not more than 15 years, or both."
That last point matters for anyone facing an ACCA notice. Without a conviction on the section 922(g) charge, the ACCA cannot apply at all. Defenses to the gun charge itself, such as disputing possession, disputing the commerce connection, or disputing the earlier conviction that supposedly bars gun possession, are therefore also defenses to the fifteen-year floor. Beat the gun charge and the enhancement falls away with it.
The three earlier convictions under § 924(e)(2)
If the gun charge is proved, the question becomes the record. The statute demands three previous convictions for a violent felony or a serious drug offense, or a mix of both. Both terms have their own definitions inside section 924(e)(2), and those definitions control. A past crime counts only if it fits them.
A serious drug offense has two branches. The first covers "an offense under the Controlled Substances Act (21 U.S.C. 801 et seq.), the Controlled Substances Import and Export Act (21 U.S.C. 951 et seq.), or chapter 705 of title 46 for which a maximum term of imprisonment of ten years or more is prescribed by law." The second covers "an offense under State law, involving manufacturing, distributing, or possessing with intent to manufacture or distribute, a controlled substance (as defined in section 102 of the Controlled Substances Act (21 U.S.C. 802)), for which a maximum term of imprisonment of ten years or more is prescribed by law." Notice what the state branch leaves out: simple possession for personal use is not in the list. The state crime must involve making, dealing, or holding with intent to deal, and it must carry at least a ten-year maximum.
A violent felony is defined as "any crime punishable by imprisonment for a term exceeding one year, or any act of juvenile delinquency involving the use or carrying of a firearm, knife, or destructive device that would be punishable by imprisonment for such term if committed by an adult, that" meets one of the listed tests. The first test is the force test: the crime "has as an element the use, attempted use, or threatened use of physical force against the person of another." The second test lists specific crimes: burglary, arson, extortion, or a crime that involves use of explosives. The statute's catch-all wording that follows, about conduct that presents a serious potential risk of physical injury, no longer counts. The Supreme Court struck it down in 2015 as too vague to enforce.
Two cautions belong here. First, the definitions look simple on paper but produce hard fights in practice, because courts must compare the elements of the old state conviction against these federal definitions, and the answer is not always clear. Second, which convictions count has changed over time as courts have issued new decisions. In one case that reached the Supreme Court, the trial court first imposed an ACCA sentence, then vacated it after appeals courts held in unrelated cases that two of the convictions relied on no longer qualified as predicates. Old assumptions about a record should never be trusted without fresh checking. Every prior conviction has to be pulled, read, and tested against the law as it stands today.
Committed on occasions different from one another
Even three qualifying convictions are not enough unless they were "committed on occasions different from one another." That phrase is quoted word for word because the whole enhancement turns on it. Three convictions from a single crime spree on one day may count as one occasion, while crimes days or weeks apart may count as separate ones. The inquiry is fact heavy: when each crime happened, where, and how the episodes relate to each other.
Because that question can add years to a sentence, the Constitution puts it in the jury box. In Erlinger v. United States, decided in 2024, the Supreme Court held: "The Fifth and Sixth Amendments require a unanimous jury to make the determination beyond a reasonable doubt that a defendant's past offenses were committed on separate occasions" for purposes of the ACCA. A judge at sentencing may not make that finding alone. If the government wants the fifteen-year floor, it must prove the separate-occasions point to a unanimous jury beyond a reasonable doubt, or the defendant must admit it in a guilty plea.
For a person facing this law, that holding has practical weight. The government must dig up decades-old police reports and charging papers, and those papers are sometimes thin or wrong about times and places. The defense gets to test that old evidence in front of a jury, under the highest standard of proof the law knows, before the mandatory floor can attach.
The penalty: what fifteen years means
A person who falls under the ACCA "shall be fined under this title and imprisoned not less than fifteen years." Fifteen years is a floor, not a suggestion. And the statute closes the usual exits: "the court shall not suspend the sentence of, or grant a probationary sentence to, such person with respect to the conviction under section 922(g)." Probation is off the table, and a suspended sentence is off the table.
Read those words the way a judge must. The fifteen-year figure is a statutory minimum, the lowest sentence the law allows once the enhancement applies. The figures elsewhere on this page, such as the fifteen-year maximum for a plain felon-in-possession case, are statutory maximums, the highest the law allows. Guideline ranges, discussed next, are a separate calculation that advises the court within those walls. None of these numbers predicts what any particular person will receive. The facts of a case change everything: which priors qualify, whether the occasions finding is proved, how the guideline math comes out, and what the judge decides within the lawful range.
The guidelines: USSG section 4B1.4
The Sentencing Guidelines carry out the ACCA through section 4B1.4, titled Armed Career Criminal. The Statutory Index in the 2025 Guidelines Manual points "18 U.S.C. § 924(e)" to "2K2.1 (see also 4B1.4)," meaning the firearms guideline is the starting point and the armed-career-criminal guideline then takes over where it produces the higher level.
Section 4B1.4 opens with a flat rule: "A defendant who is subject to an enhanced sentence under the provisions of 18 U.S.C. § 924(e) is an armed career criminal." From there it sets the offense level as the greatest of three measures: the level from the ordinary guideline chapters, the career-offender level if that applies, or the ACCA-specific level. That ACCA level is 34 "if the defendant used or possessed the firearm or ammunition in connection with either a crime of violence, as defined in §4B1.2(a), or a controlled substance offense, as defined in §4B1.2(b), or if the firearm possessed by the defendant was of a type described in 26 U.S.C. § 5845(a)," and "33, otherwise." A person who accepts responsibility can still earn the usual reduction off that level.
Criminal history works the same way, taking the greatest of three measures: the ordinary criminal history category, the career-offender category if it applies, or the ACCA-specific category. That category is Category VI "if the defendant used or possessed the firearm or ammunition in connection with either a crime of violence" or a controlled substance offense, or if the gun was of the type described in the firearms tax law, and "Category IV" otherwise. In plain terms, those ACCA numbers are floors, not fixed results. A person who possessed the gun in connection with a violent or drug crime starts at no lower than level 34 and Category VI before any acceptance reduction, while everyone else under the ACCA starts at no lower than level 33 and Category IV. The final level or category can be higher if another measure is greater.
Three fine points in the commentary often matter. First, the guideline definitions of violent and drug crimes used for the level 34 and Category VI triggers are not the same definitions as the ACCA statute uses for the predicates, so a conviction can count at one step and not the other. Second, the ordinary time limits for counting criminal history do not decide whether someone is an armed career criminal; very old convictions can still trigger the statute. Third, when an ACCA sentence is imposed alongside a sentence for using a gun during a violent or drug-trafficking crime, the guideline does not apply the higher ACCA level and category, because the other sentence already accounts for that conduct. How these layers interact is part of what a federal sentencing hearing is for.
How the ACCA differs from section 924(c)
The charge most often confused with the ACCA is 18 U.S.C. § 924(c), the law behind our firearm in furtherance page. The two could not work more differently, and mixing them up leads to bad expectations.
Section 924(c) punishes "any person who, during and in relation to any crime of violence or drug trafficking crime (including a crime of violence or drug trafficking crime that provides for an enhanced punishment if committed by the use of a deadly or dangerous weapon or device) for which the person may be prosecuted in a court of the United States, uses or carries a firearm, or who, in furtherance of any such crime, possesses a firearm." It then requires that the person "shall, in addition to the punishment provided for such crime of violence or drug trafficking crime" receive at least five years, at least seven if the gun was brandished, and at least ten if it was discharged. And it orders that "no term of imprisonment imposed on a person under this subsection shall run concurrently with any other term of imprisonment imposed on the person," which means the time stacks on top of everything else, day for day.
Compare that with the ACCA. Section 924(c) is its own charge, proved by what the person did with a gun during this crime, and its time runs consecutively to all other time. The ACCA is not its own charge, is proved by what the person was convicted of years ago, and sets the floor for the felon-in-possession sentence itself rather than adding a stack on top. A case can involve one, the other, or in theory both, and the defense for each runs on separate tracks.
Defenses that arise under this law
Every ACCA case is really several cases in one, and the defense runs at each layer.
Attack the predicates one by one. The government must show three convictions that fit the federal definitions quoted above. That means pulling the charging document, the statute of conviction, and the judgment for each old case and testing them element by element. State labels do not decide the question. A state conviction called burglary may or may not fit the federal meaning, and a state drug case may fall outside the list if it involved simple possession rather than making or dealing. Because courts keep refining which convictions fit, a record that looked like three predicates years ago may look different today.
Fight the occasions finding. Even qualifying convictions must have happened on separate occasions. Crimes committed close together in time and place, during one continuous episode, may count as one occasion rather than several. After Erlinger, the government must convince a unanimous jury beyond a reasonable doubt, and old records often make poor proof. Missing dates, vague locations, and plea papers that say nothing about timing all cut against the government when the standard is proof beyond a reasonable doubt.
Defend the gun charge itself. The ACCA needs a section 922(g) conviction first. Everything that can defeat the possession charge, from disputing that the person possessed the gun, to disputing the interstate commerce link, to disputing the earlier conviction that made possession unlawful, defeats the enhancement too.
Litigate the guideline math. Whether the level is 34 or 33, and whether the category is VI or IV, turns on whether the gun was possessed in connection with a violent or drug crime or was of a special type. Those phrases have their own guideline definitions, and the acceptance-of-responsibility reduction remains available. Small differences at this step can move the advised range by years, so each trigger has to be proved, not assumed.
What to do if this law is aimed at you
An ACCA allegation usually arrives in a notice or in plea talks, long before sentencing. The record the government relies on should be gathered at once: judgments, charging papers, plea transcripts, and sentencing minutes for every old case, plus the reports behind them. Gaps and errors in decades-old files are common, and each one is a point the defense can press, first with the prosecutor and ultimately before a jury on the occasions question.
Do not assume the math is fixed. The statute sets a floor of fifteen years with no probation, and the guideline sets high starting levels, but every input into both calculations can be challenged. Talk to a lawyer early, bring every paper you have from the old cases, and do not discuss the facts with anyone except your lawyer. The numbers on this page are statutory minimums, maximums, and guideline levels, not predictions, and the facts of a case change everything.