State Guide
Age of Consent in Idaho
A plain-English guide to the age of consent in Idaho, cited to Idaho Code § 18-6101. Idaho has a genuine gap-based allowance for 16 and 17 year olds, but none at all under 16.
Close-in-age allowance under 3 years, ages 16–17 onlyIdaho at a glance
The core figures from this guide, in one place.
| Age of consent | 18 |
|---|---|
| Governing statute | Idaho Code § 18-6101 (Rape Defined) |
| Close-in-age mechanism | Not covered if gap is under 3 years, victim 16–17 only |
| Age-based defense, if any | None; mistake of age is not a defense |
| Related offense | Sexual abuse of a minor under 16 — Idaho Code § 18-1506 |
Overview
Idaho sets its age of consent at 18. Idaho Code Section 18-6101 defines rape to include sexual penetration with someone under 16 by anyone 18 or older, with no allowance for how close the two people are in age. A separate provision covers a victim 16 or 17, but only reaches an offender at least three years older.
Sources describe this differently: some call the three-year provision a genuine Romeo and Juliet allowance, while others say Idaho has no such law at all, since it only applies at the 16-17 tier and offers nothing for a younger victim. Both descriptions are accurate about the same underlying rule; they differ only in whether a narrow, single-tier allowance counts as a “Romeo and Juliet law” in the reader’s sense of the term.
Age of consent in Idaho
Idaho Code Section 18-6101(1) makes it rape for anyone 18 or older to sexually penetrate someone under 16, regardless of the age gap. Section 18-6101(2) separately covers a victim 16 or 17, requiring the perpetrator to be at least three years older, measured precisely from date of birth to date of birth.
Close-in-age rules in Idaho
The age gap allowance applies only to the 16-17 tier under Section 18-6101(2). If the perpetrator is less than three years older than a 16 or 17 year old, this specific provision does not reach the conduct.
Exceptions and defenses
Idaho courts have held that a mistake about the victim’s age is not a defense to rape, even if the mistake was reasonable or the minor lied about their age. Consent is also not a defense. Marriage to the victim is a stated exclusion from Section 18-6101 for both age-based subsections. A related offense, sexual battery of a minor 16 or 17 where the perpetrator is five or more years older, uses a wider gap threshold than the rape statute’s three years.
Applicable statutes
The codified Idaho law this guide is drawn from.
Practical examples
Example 1. A 17-year-old and a 19-year-old, a two-year gap. Because the gap is under three years, Section 18-6101(2) does not reach this conduct.
Example 2. A 17-year-old and a 21-year-old, a four-year gap. This exceeds three years, so rape under Section 18-6101(2) applies.
Example 3. A 15-year-old and an 18-year-old, a three-year gap. Because the victim is under 16, the three-year allowance does not apply at all, and Section 18-6101(1) applies regardless of the gap.
Frequently asked questions about Idaho
What is the age of consent in Idaho?
18. Idaho Code Section 18-6101 makes it rape for anyone 18 or older to have sexual intercourse with someone under 16, and separately addresses a 16 or 17 year old victim.
Does Idaho have a Romeo and Juliet law?
Sources disagree on the label, but the underlying rule is consistent: a three-year gap allowance exists only for a 16 or 17 year old victim, with nothing comparable for a younger victim.
Does this allowance help a couple where one person is 15?
No. The three-year allowance applies only where the victim is 16 or 17. For a victim under 16, any perpetrator 18 or older is covered by the statute regardless of the gap.
Does a mistaken belief about age count as a defense?
No. Idaho courts have held that a mistake about the victim’s age is not a defense, even if it was reasonable or the minor misrepresented their age.
Are married couples treated differently?
Yes. Marriage to the victim is a stated exclusion from both age-based subsections of Section 18-6101.
Official sources
Primary and official sources this guide is built from.
Two age bands, two different rules
Idaho’s allowance exists at only one of its two age tiers.
| Victim age | Rule |
|---|---|
| Under 16 | Any perpetrator 18+ is covered, regardless of gap |
| 16 or 17 | Only covered if perpetrator is 3+ years older |
About this guide
Who wrote it, who reviewed it, and when it was last checked.
RomeoAndJulietLaw.com Editorial Team
Drafted from the Idaho Code and Idaho Supreme Court case law, cross-checked against multiple independent legal references.
Pending attorney review
This guide has not yet been checked by a licensed Idaho 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 Idaho Code as of 26 July 2026. It has not yet been reviewed by a licensed Idaho attorney; treat it as sourced and current-as-drafted, not as attorney-verified, until the reviewer field above is updated.