By FindLaw Staff | Legally reviewed by Nicole Prebeck, Esq. | Last reviewed January 27, 2023
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State laws dictate the grounds under which an annulment may be granted and which types of marriage are prohibited. Examples of marriages that are prohibited are those between closely related family members or those where a previous marriage was not ended either through a divorce or a spouse's death. In Montana, laws related to civil annulments and prohibited marriages are very similar to those of other states.
In Montana, certain types of marriage are prohibited. These include marrying your first cousin or other closely related family member such as a sibling or parent. In addition, you can't get married if you already have a spouse. You'll have to have a formal divorce first. Also, you have to be of legal age, unless you obtain the consent of a parent or guardian.
Same-sex marriage is now legal in the state of Montana. In 2015, the U.S. Supreme Court ruled that same-sex marriage is protected and guaranteed under the Fourteenth Amendment's Equal Protection Clause. In that year, the U.S. Supreme Court did so in a case called Obergefell v. Hodges.
The basics of Montana's laws related to civil annulments and prohibited marriages are listed in the following chart. See FindLaw's Marriage Law Overview section for additional articles.
| Grounds for Annulment | Under 40-1-402, the following are reasons a person may pursue an an annulment to their marriage:
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| Time Limits for Obtaining Annulment | Under 40-1-402, the time limits for pursuing an annulment are:
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| Legitimacy of Children | Under 40-1-401, children that are born to legally invalid marriages or marries that are annulled are considered legitimate. |
| Prohibited Marriages | Under 40-1-401, the following types of marriage are prohibited:
Under 45-5-611, bigamous marriages are prohibited. Bigamous marriages are marriages where someone is married to more than one person. |
Note: Montana marriage laws are constantly changing. Contact a Montana family law attorney , or conduct your own legal research to verify the state law(s) you are researching.
Consider reviewing the following resources for more information about laws in Montana, including those related to civil annulments and prohibited marriages:
Consider reviewing the following resources for more information about laws and legal issues related to civil annulments, prohibited marriages, and marriage in general:
If you're considering an annulment or in a marriage that is legally invalid, it's always best to contact a qualified family law attorney near you. They can help you will all your legal concerns related to to these issues.
Contact a qualified attorney.
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