Policy Factsheet

Enforcement of Minimum Legal Drinking Age (MLDA) Laws

Reasons for Policy

  • Traffic crashes are the leading cause of death among adolescents and 1/3 of those deaths involve alcohol.2
  • Studies have shown that teens that start drinking before they are 21 are more likely to drink heavier as adults, compared to those that wait until they are 21.2
  • The majority of alcohol outlets regularly sell alcohol to minors.2

Community Groups

  • Local Government
  • Local Justice System
  • Local Law Enforcement

Policy Components

  • Greater enforcement of minimum age sales laws
  • Efforts to reduce use of false identification
  • Increased restrictions on home delivery of alcohol

Desired Outcomes

  • Lower rates of underage drinking
  • Lower rates of traffic crashes involving alcohol
  • Lower rates of other alcohol-related health and social problems (e.g., crime, unintentional injuries)

Level of Evidence Available to Evaluate Effectiveness of Policy

For all policies we describe on this website, we have applied the Standards of Evidence as defined by Flay et al. (2005) in the Standards of Evidence document published by Prevention Science.

The effectiveness level of this policy is 1: Evidence-Based Policies Meeting Criteria for Effectiveness.

The levels of effectiveness as noted are:

  1. meets criteria for policy effectiveness (consistent, positive outcomes from at least two high-quality experimental or quasi-experimental trials using a comparison group or interrupted time series design);
  2. consistent evidence available linking policy with positive outcomes from high-quality observational studies only;
  3. insufficient evidence available for policy or policy components.

Achievable Results

On average, higher legal drinking ages can achieve:

  • Significant reductions in alcohol consumption among underage youth2
  • Significant reductions in traffic crashes2
  • Lower rates of alcohol-related health and social problems (e.g., unintentional injuries, crime); although evidence is inconsistent across some outcomes2

Community Examples

Links to Policy Examples

Be sure to check with your state, county, and municipal governments regarding potential existing laws that may impede any new policy development.


  1. Flay, BR, Biglan, A, Boruch, RF, Ganzalez Castro, F, Gottfredson, D, Kellam, S, Moscicki, EK, Schinke, S, Valentine, JC, & Ji, P (2005). Standards of evidence: Criteria for efficacy, effectiveness and dissemination. Prevention Science, 6(3), 151-175.  

  2. Wagenaar AC & Toomey TL (2002). Effects of minimum drinking age laws: Review and analyses of the literature from 1960 to 2000. Journal of Studies on Alcohol, Supplement No. 14, 206-225.