Can Adults Attend High School in Idaho? Here’s the Line

A Grown-Up “Teen” In Ohio, And The Question It Raises In Idaho

A disturbing story out of Ohio raises a question about Idaho policy. In September 2025, prosecutors said a 24-year-old man in Perrysburg, Ohio pleaded guilty after enrolling in high school while posing as a 16-year-old. The case made national headlines. Thankfully, I couldn’t find any instances of anything like this happening in Idaho. And granted, the guy in Ohio was lying about his age. Still, it raised the question about the upper age limit to attend public school in the state of Idaho legitimately.

Idaho’s Upper Age Limit For K-12

Idaho law is clear on public school age. It runs from 5 through 21. That’s in Idaho Code §33-201. Children in Idaho are required to attend school at ages 7 through 16 under §33-202. That means you can potentially attend public high school in Idaho up to the age of 21. After 21, you’ve aged out.

Diploma Options If You’re In Idaho And Still Under 21

The good news is that if you’re close to the finish line, Boise has a few options for you to obtain a diploma in the public school system. In addition to attending regular school, Frank Church High School is the district’s alternative setting for students who need a nontraditional approach to graduation. If you need flexible scheduling, Boise Evening School enrolls through Boise Online School.

What If You’ve Aged Out But Still Want A Diploma?

If you’re over 21, your chances at public school are over. But the good news is you still have plenty of options if you want to graduate with a high school education. You can go for an Adult Workforce High School Diploma through state-approved providers. Or you can get a GED. College of Western Idaho offers free prep and testing scheduled through GED.com.