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Legal Marriage Age

Written by Dr. Madeleine Roberts
Published on March 20, 2024
Research Highlights

While every state sets a minimum marriage age at or above 18 years old, most states allow minors to be married with parental or judicial consent.

Marriage of minors is uncommon in MO and the U.S. compared to low-income nations.

Being married as a child is associated with negative social, economic, and health outcomes.

Eleven states do not allow people under the age of 18 to marry.

Every state has set the minimum age of marriage at 18 years old, except for NE (19 years old) and MS (21 years old).

Most states allow exceptions to their minimum marriage age (Figure 1). The most common exception allows marriage of minors as young as 15 years old with parental consent. CA, MS, NM, and OK allow for marriage between children under the marriage age, with parental consent but without setting a minimum age. Other exceptions that can allow marriage of people below the minimum age include:

  • A judge provides consent/approval
  • One party is pregnant or has recently given birth
  • The minor is emancipated

12 states do not allow exceptions to their minimum marriage age: CT, DE, MA, MI, MN, NJ, NY, PA, RI, VT, WA (18 years old), KY (17 years old).

  • Legislation is pending in 8 states (CA, HI, IL, KS, MO, NH, SC, VA) to set the minimum age of marriage at 18 years old without exception.

In MO, the minimum marriage age is 18 years old, or 16 years old with parental consent (RSMO 451.090). MO statute prevents someone over the age of 21 from marrying a person under 18 years old with no exceptions.

Figure 1. Each U.S. state is colored by the minimum age allowed to enter marriage, with exceptions.

In the U.S., marriage of children is more common among specific cultural groups.

The estimated prevalence of marriage of 15-17 year olds in MO (4.9 per 1,000 children surveyed) is lower than the national rate (6.2 per 1,000 children surveyed) (Koski 2018). Compared to the national marriage rates of 18-19 year olds (18.4 per 1,000 surveyed) and 20-24 year olds (107.4 per 1,000 surveyed), minors marry much less frequently (McClendon 2016).

  • In the U.S. more girls are married than boys (6.8 vs 5.7 per 1,000 surveyed, Koski 2018).
  • In the U.S., most marriages of children took place between a minor and an adult over the age of 18 (Van Roost 2021).
  • 82 marriages involving people 16-17 years old (and 0 marriages involving people under the age of 16) took place in MO in 2021 (DHSS Vital Statistics 2021).

Marriage timing varies between U.S. regions, cultures, and religions. Being married as a child is more common for Hispanic women, low-income women, women from the Southern U.S., and people of Mormon and conservative Protestant religious backgrounds (Koski 2018).

The reasons for marriage as a child are context specific (Muthengi 2021). Most studies looking at reasons for the marriage of children focus on low-income countries, finding that the higher incidence of early marriage of girls is connected to their cultural traditions as well as lower education and economic opportunities for girls.

American cultural justifications for the marriage of minors have not been well-studied. Case reports indicate that pregnant girls face pressure to marry to avoid stigma associated with premarital sex (Koski 2018). In many states, the legal marriage age is lower than the legal age of consent for sex, and there are marital exceptions to statutory rape. Therefore, marriage laws can be used to avoid repercussions from statutory rape laws (Van Roost 2021).


Married minors experience long-term adverse outcomes.

Marriage of children is widely considered to be a human rights abuse due to many long-term adverse consequences (United Nations Population Fund 2012). UN Sustainable Development Goal 5.3 commits member nations including the U.S., to ending marriage for all people under 18 years old by 2030.

Children, especially girls, who marry under 18 years of age are more likely than their unmarried peers to experience (Omidakhsh 2020, Koski 2018, Le Strat 2011, Dahl 2010):

  • Lower educational attainment
  • Living in poverty as an adult
  • Intimate partner violence
  • High-risk adolescent pregnancies
  • Mental health and substance use disorders throughout their lifetime
  • Less satisfying marriages that are more likely to result in divorce or separation



MO Department of Health and Human Services (2021) Vital Statistics 2021. https://health.mo.gov/data/vitalstatistics/mvs21/Preface.pdf

Dahl GB (2010) Early teen marriage and future poverty. Demography, 47(3), 689–718. https://link.springer.com/article/10.1353/dem.0.0120

Koski A, Heymann J (2018) Child Marriage in the United States: How Common Is the Practice, And Which Children Are at Greatest Risk? Perspectives on Sexual and Reproductive Health, 50(2), 59–65. https://onlinelibrary.wiley.com/doi/abs/10.1363/psrh.12055

Le Strat Y, Dubertret C, Le Foll B (2011) Child marriage in the United States and its association with mental health in women. Pediatrics, 128(3), 524–530. https://pubmed.ncbi.nlm.nih.gov/21873691/

McClendon D, Sandstrom A (2016) Child marriage is rare in the U.S., though this varies by state. Pew Research Center. https://www.pewresearch.org/short-reads/2016/11/01/child-marriage-is-rare-in-the-u-s-though-this-varies-by-state/

Muthengi E, Olum R, Chandra-Mouli V (2021) Context Matters—One Size Does Not Fit All When Designing Interventions to Prevent Child Marriage. Journal of Adolescent Health, 69(6), S1-S3. https://www.jahonline.org/article/S1054-139X(21)00468-7/pdf

Omidakhsh N, Heymann J (2020) Improved child marriage laws and its association with changing attitudes and experiences of intimate partner violence: A comparative multi-national study. Journal of Global Health, 10(1). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7101085/pdf/jogh-10-010707.pdf

United Nations Populations Fund (2012) Marrying Too Young. United Nations Populations Fund. https://www.unfpa.org/publications/marrying-too-young

Van Roost K, Horn M, Koski A (2022) Child Marriage or Statutory Rape? A Comparison of Law and Practice Across the United States. Journal of Adolescent Health, 70(3), S72–S77. https://www.jahonline.org/article/S1054-139X(21)00552-8/fulltext#:~:text=Results,from%20the%20definition%20of%20crimes.

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