State Guide
Age of Consent in Montana
A plain-English guide to the age of consent in Montana, cited to Mont. Code Ann. § 45-5-503. Montana has no close-in-age exemption, and even protects some 16 and 17 year olds from much older partners.
No exemption — age gap only raises the mandatory minimumMontana at a glance
The core figures from this guide, in one place.
| Age of consent | 16 |
|---|---|
| Governing statute | Mont. Code Ann. § 45-5-503 (Sexual Intercourse Without Consent) |
| Close-in-age exemption | None, at any gap, under 16 |
| Additional protection, ages 16–17 | Applies if partner is 10+ years older |
| Related offense | Sexual assault (contact only) — Mont. Code Ann. § 45-5-502 |
Overview
Montana does not have a separate “statutory rape” statute. Instead, anyone under 16 is legally defined as incapable of consenting to sexual intercourse, which means sexual intercourse with someone under 16 is automatically sexual intercourse without consent under Mont. Code Ann. Section 45-5-503, regardless of the younger person’s apparent willingness.
Montana has no close-in-age exemption of any kind for this offense. Two people both under 16 in a consensual relationship can both potentially face charges, and there is no lesser tier for a small age gap.
Age of consent in Montana
Section 45-5-503(1) makes it a crime to have sexual intercourse with someone incapable of consent, which by definition includes anyone under 16. The base penalty is severe: life imprisonment or up to 20 years. Section 45-5-503(3)(a) raises the mandatory minimum to 4 years specifically where the victim is under 16 and the offender is 4 or more years older, or where bodily injury occurred. This is an enhancement to sentencing, not a separate coverage threshold; the underlying offense already applies regardless of the gap.
Close-in-age rules in Montana
Separately, Montana extends some protection to 16 and 17 year olds beyond the general age of consent: a person 16 or 17 is also treated as incapable of consent if the other person is at least 10 years older. This is a distinct, additional layer, not a close-in-age allowance, and it works in the opposite direction of most states’ Romeo and Juliet provisions, protecting older teenagers from adults with a very large age gap rather than exempting a small one.
Exceptions and defenses
A person may not be convicted under Section 45-5-503 based on the age of their spouse, a stated marital exclusion. This guide did not find a reliable official source describing a general mistake-of-age defense to this statute, and sources describing Montana law are consistent that a genuine, good-faith mistake about the other person’s age does not appear to be an established defense here.
Applicable statutes
The codified Montana law this guide is drawn from.
Practical examples
Example 1. A 15-year-old and a 16-year-old, a one-year gap. Because the victim is under 16, this is still sexual intercourse without consent under Montana law, regardless of the small gap.
Example 2. A 15-year-old and a 21-year-old, a six-year gap. This meets the 4-year threshold, raising the mandatory minimum sentence to 4 years.
Example 3. A 17-year-old and a 28-year-old, an eleven-year gap. Because the gap exceeds 10 years, the 17-year-old is also treated as incapable of consent under this separate provision.
Frequently asked questions about Montana
What is the age of consent in Montana?
16. Montana defines anyone under 16 as legally incapable of consenting, making sexual intercourse with them sexual intercourse without consent under Mont. Code Ann. Section 45-5-503.
Does Montana have a Romeo and Juliet law?
No. Montana has no close-in-age exemption for a victim under 16. A four-year gap only raises the mandatory minimum sentence; it does not create or remove criminal liability.
Can two teenagers both under 16 be charged?
Yes, in principle. Because there is no close-in-age exemption, two people both under 16 in a consensual relationship could both face charges, though sources describe this as rare in practice.
Are 16 and 17 year olds ever protected beyond the general age of consent?
Yes. A 16 or 17 year old is also treated as incapable of consent if their partner is at least 10 years older, a separate protection layered on top of the general rule.
Are married couples treated differently?
Yes. A person cannot be convicted under this statute based on the age of their spouse.
Official sources
Primary and official sources this guide is built from.
Montana vs. a genuine-exemption state
Montana sits at the strict end of the spectrum.
| Feature | Montana | A close-in-age-exemption state |
|---|---|---|
| Small age gap, victim under 16 | No effect on liability | May remove liability entirely |
| Large age gap effect | Raises mandatory minimum | Varies |
| Protection for 16–17 year olds | Yes, if partner 10+ years older | Varies |
About this guide
Who wrote it, who reviewed it, and when it was last checked.
RomeoAndJulietLaw.com Editorial Team
Drafted from the Montana Code Annotated and the Montana Department of Justice’s sexual assault statute reference, cross-checked against multiple independent legal references.
Pending attorney review
This guide has not yet been checked by a licensed Montana attorney. It is sourced and cited, but should not be treated as attorney-reviewed until this line is updated with a named reviewer.
Primary source for this guide
Editorial notes
This guide reflects the Montana Code Annotated as of 26 July 2026. It has not yet been reviewed by a licensed Montana attorney; treat it as sourced and current-as-drafted, not as attorney-verified, until the reviewer field above is updated.