Insight Online School

Insight online High School is another free homeschool option for students living in California. According to their website

What are the location and age restrictions?
Students must be residents of Los Angeles, Orange, Ventura, San Bernardino, or Kern County, and must be 19 years of age or younger when they enroll. Students under 14 must provide evidence of completion of eighth grade. Some exceptions apply for students 20 and 21 years of age who have been continuously enrolled in high school and making progress toward a diploma.