The age of consent in Missouri is 17, but the state uses a tiered structure that also permits some sexual activity involving 14-, 15-, and 16-year-olds when the partner is close in age. Any sexual activity with someone under 14 is a top-level felony regardless of the other person’s age, and adults 21 or older cannot legally have sex with anyone under 17.
The Three Age Brackets
Missouri’s sexual offense statutes work through age tiers rather than a single line:
- Under 14. Sexual intercourse with anyone under 14 is first-degree statutory rape, and the partner’s age is irrelevant. There is no close-in-age allowance at this level.1Missouri Revisor of Statutes. Missouri Code 566.032 – Statutory Rape and Attempt to Commit, First Degree, Penalties
- 14 through 16. A person in this range cannot legally consent to sex with someone more than four years older, or with anyone 21 or older. A 15-year-old and an 18-year-old are within the permissible range. A 15-year-old and a 22-year-old are not.2Missouri Department of Health and Senior Services. Missouri Minor Consent Laws
- 17 and older. A 17-year-old can consent to sexual activity with anyone who is at least 14.3Missouri Revisor of Statutes. Missouri Code 566.034 – Statutory Rape, Second Degree, Penalty
The second-degree statutory rape statute specifically targets adults 21 and older who have intercourse with someone under 17.3Missouri Revisor of Statutes. Missouri Code 566.034 – Statutory Rape, Second Degree, Penalty That means an 18-year-old dating a 16-year-old generally falls outside the statute, while a 21-year-old with a 16-year-old does not.
How the Close-in-Age Rule Works
Missouri’s close-in-age framework functions like what other states label a “Romeo and Juliet” law, though Missouri statutes don’t use that phrase. A 14-, 15-, or 16-year-old can engage in consensual sexual activity with someone no more than four years older.2Missouri Department of Health and Senior Services. Missouri Minor Consent Laws
The math has a sharp edge. A 16-year-old and a 20-year-old sit exactly four years apart and stay legal. If the older partner turns 21 while the younger partner is still 16, the relationship crosses into second-degree statutory rape territory under Missouri Code 566.034.3Missouri Revisor of Statutes. Missouri Code 566.034 – Statutory Rape, Second Degree, Penalty Birthdays matter.
And the allowance never reaches children under 14. Any sexual activity with a partner that young is first-degree statutory rape no matter how close in age the older partner is.1Missouri Revisor of Statutes. Missouri Code 566.032 – Statutory Rape and Attempt to Commit, First Degree, Penalties
Penalties by Bracket
Consequences scale sharply with the younger partner’s age.
- First-degree statutory rape (victim under 14). A felony punishable by life imprisonment or a prison term of at least five years. If the victim is under 12 or the offense qualifies as an aggravated sexual offense, the minimum jumps to ten years.1Missouri Revisor of Statutes. Missouri Code 566.032 – Statutory Rape and Attempt to Commit, First Degree, Penalties
- Second-degree statutory rape (offender 21+, victim under 17). A class D felony.3Missouri Revisor of Statutes. Missouri Code 566.034 – Statutory Rape, Second Degree, Penalty
- First-degree statutory sodomy (victim under 14). Carries the same penalty structure as first-degree statutory rape, including a minimum of five years and up to life imprisonment.4Missouri Revisor of Statutes. Missouri Code 566.062 – Statutory Sodomy and Attempt to Commit, First Degree, Penalties
Persistent or predatory sexual offenders face enhanced sentencing beyond these baseline ranges. Even attempting first-degree statutory rape or sodomy carries the same felony classification and penalties as a completed offense.1Missouri Revisor of Statutes. Missouri Code 566.032 – Statutory Rape and Attempt to Commit, First Degree, Penalties
Is Mistake of Age or the Teen’s Consent a Defense?
It depends entirely on which age bracket is involved.
When the charge involves a victim under 14, Missouri flatly bars a mistake-of-age defense. It does not matter if the child looked older, showed a fake ID, or claimed to be 18. The law treats the age element as strict liability. The same statute makes clear that the victim’s consent is never a defense when the victim is under 14. A 13-year-old saying “yes” is not legally meaningful consent in Missouri.5Missouri Revisor of Statutes. Missouri Code 566.020 – Mistake as to Age, Consent Not a Defense, When
When the victim is under 17 but at least 14, Missouri does allow an affirmative defense: the defendant can argue they reasonably believed the person was 17 or older.5Missouri Revisor of Statutes. Missouri Code 566.020 – Mistake as to Age, Consent Not a Defense, When “Affirmative defense” means the defendant carries the burden of proving the belief was reasonable. Vague claims like “she looked old enough” rarely clear that bar. Credible evidence, such as a fake ID the defendant actually saw, carries more weight.
When a Teacher, Coach, or School Employee Is Involved
Age of consent rules do not fully cover school settings, and this trips people up. Missouri criminalizes sexual contact between a student and a school authority figure regardless of whether the student is technically above the age of consent. Under the state’s sexual contact with a student statute, a teacher, coach, or other school authority figure who engages in sexual contact with a student commits a class E felony.6Missouri Revisor of Statutes. Missouri Code 566.086 – Sexual Contact With a Student The student’s willingness is not a defense. A 17- or 18-year-old high school student can legally consent to sex with someone their own age, but not with a teacher at their school.
Sex Offender Registration After a Conviction
A conviction for a statutory sex offense in Missouri triggers mandatory sex offender registration. Anyone convicted of a listed offense must register with the chief law enforcement official in their county within three business days of being sentenced, released from incarceration, or placed on probation.7Missouri Revisor of Statutes. Missouri Code 589.400 – Registration of Certain Offenders
Missouri assigns registrants to one of three tiers:
- Tier I. Annual in-person reporting during the registrant’s birth month. Covers offenses like second-degree sexual abuse when the victim is an adult, and first-offense sexual misconduct involving a child when the sentence is under one year.8Missouri Revisor of Statutes. Missouri Code 589.414 – Tier Classifications for Sex Offender Registration
- Tier II. Semiannual in-person reporting. Includes second-degree statutory rape and second-degree statutory sodomy.8Missouri Revisor of Statutes. Missouri Code 589.414 – Tier Classifications for Sex Offender Registration
- Tier III. Quarterly in-person reporting. Reserved for the most serious offenses, including first-degree statutory rape and first-degree statutory sodomy.
Registration brings restrictions on where a registrant can live, where they can work, and how freely they can travel. Under federal law, registered sex offenders who plan to travel outside the United States must report their itinerary to their home jurisdiction at least 21 days in advance, and failing to do so can result in separate federal criminal charges. Anyone who moves to a new state must register there within three business days of arriving.9eCFR. 28 CFR Part 72 – Sex Offender Registration and Notification