Quoting Missouri Emancipation Law
In Missouri, a minor may be emancipated in one of three ways:
1) your parents may give express consent to a court that they are waiving their parental rights;
2) your parents may give implied consent, which would apply in situations where you have been living on your own, supporting yourself, and for all practical purposes your parents have relinquished their parental rights; and
3) you experience a significant change in your societal status-such as an enlistment in the military or marriage.
As in Kansas, emancipation requires the ruling of a judge.