Glossary

Mandatory minimum sentence

A law setting a minimum prison term that a judge must impose for a specific crime, regardless of circumstances.

Also called: mandatory minimum sentence, mandatory minimums, sentencing guidelines

A mandatory minimum sentence is a statute that requires a judge to impose at least a specified prison term upon conviction for certain offenses, such as drug trafficking or firearm crimes, leaving the judge little or no room to consider individual circumstances. Only prosecutors' charging decisions, plea bargains, or narrow exceptions can alter the result.

They proliferated in the 1980s and 1990s during the war on drugs, including the Anti-Drug Abuse Act of 1986, which set sentences by drug quantity and created a 100-to-1 disparity between crack and powder cocaine, later reduced to 18-to-1 by the Fair Sentencing Act of 2010. "Three strikes" laws and firearms enhancements, such as under 18 U.S.C. § 924(c), are also mandatory minimums. The First Step Act of 2018, a bipartisan law, reduced some mandatory minimums for nonviolent drug offenses and made the Fair Sentencing Act retroactive.

Supporters argue that they ensure consistency and certainty of punishment, deter crime and give prosecutors leverage to obtain cooperation. Critics, a coalition that includes civil-liberties groups and some conservatives and libertarians, argue that they lead to excessive sentences, shift power from judges to prosecutors, contribute to mass incarceration and disproportionately affect minorities. Reform has been an area of left-right cooperation, though disagreements remain about violent crime and firearms. See also cashless bail and civil asset forfeiture and void for vagueness.

Last reviewed November 8, 2026

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Related terms

Cashless bail Reforms that limit or end the use of money bail to hold people charged with crimes before trial, replacing it with release conditions or risk assessments. Civil asset forfeiture A legal process by which government seizes property it alleges is connected to a crime, without necessarily charging or convicting the owner. Void for vagueness The rule that a law is unconstitutional if it is so unclear that ordinary people cannot know what it forbids. Broken windows policing A policing strategy built on the theory that enforcing minor offenses and disorder helps prevent more serious crime. Defund the police A slogan from 2020 calling for reducing police budgets and shifting money to social services, with meanings ranging from modest cuts to abolition.