Mandatory minimum sentencing statutes specify that certain criminal offenses hold a particular sentence that must be adhered to without exception. For such offenses, judges specify the maximum term but cannot sentence the offender to less than the statutory minimum. Some mandatory minimum sentences restrict parole eligibility as well. Mandatory minimum sentences exist at both the state and federal levels and are most commonly applied to repeat or habitual offending, drunk driving offenses, drug offenses, weapon offenses, and sex offenses. These statutes significantly reduce judicial discretion by eliminating a judge’s ability to take into account mitigating factors, such as past criminal history, instead by applying a one-size-fits-all approach to sentencing. After reviewing the history of mandatory minimum sentences, this entry discusses sentencing reform.