That was the same situation that we were in. I had thought about starting him a year early, but then we would have had to buy the curriculum. There are different ways you could do K12. We do the online public school option. We do not get to pick out our curriculum, but it is free. They send us everything we need for the entire school year and if they advance a grade, at any time during the year, they send you the next set of material. There is also the option to buy the curriculum as an individual and I think there is also a private school option. Buying your own curriculum would allow you to select which courses you want and omit others, but it is not free. You would have to buy each class you want. I am not sure on the prices, but I know the information is available on their website. Some school districts offer the option of doing half-public school and half-homeschool, but you would need to talk to your specific school district about that.