What is the law re: withdrawing children from private school now?

You can certainly withdraw him and go through the steps of setting up homeschooling (in some areas, you can set up independent study through your local district, which is likely to be the simplest; there are also charter schools set up to facilitate this). However, you will almost certainly need to pay tuition to your child's current school for the balance of the year anyway--your contract will specify this, but almost all become binding at the start of the school year. Given that there is only a month left of school, I'm not sure there's a huge amount to gain here. I would focus on working with his current teacher to get through to the end of the school year, and then withdraw him for next year and look for other options for the fall.

You should review the contract you signed. My daughter goes to a private school and the contract we signed basically says we're responsible for the full tuition if we withdraw her. If you have the tuition refund insurance you might be able to use that but I think you would still be on the hook for a portion of the remaining tuition.

We were considering doing the same, although to help support teachers, we are paying for the rest of the year and using supplemental material for each of our kids (grades 2, 4 and 7). It has worked out very well for us. Our kid’s school froze their grades and all work is just for learning. I will say, for us, this model has worked very well. 

Also, we are talking to the school to see if they’d do a hybrid model next year. We do not plan on allowing our kids to attend school (frontline workers so we have a “unique” lens). It would make sense to charge students less in tuition for this model but it still ensures that tuition money is coming in.

If you have a month to go before your private school year ends, I would talk with your child's teacher and see what can be changed to make what's left of the school year better for your son. There is a myth that homeschooling is easy. Home learning done well takes much intentionality and flexibility about what best suits the child and family in terms of how to support learning. Many families who homeschooled before the pandemic hit the Bay Area had larger learning environments because our communities are learning labs where we enrich our curriculum to real-world experiences. Sheltering in place has caused interruptions in routines for all children. However, the silver lining of massive disruption is clear insight into what is the best course of action going forward. What are your thoughts on education? How does your child learn academically and social-emotionally? Those of us who homeschool either through a Private School Affidavit or charter school spend a lot of time manifesting what the purpose of education should be in harmony with our child's learning style. It is not easy but so worth it. If homeschooling is the direction you would like to pursue for your family contact homeschooling groups and organizations in your area.        

It might be useful to start with the terms of your contract. One that is relevant is the force majeure clause. This likely specifies that you are on the hook for tuition BUT implicit in any force majeure contract is that the school must continue to provide as much as possible in terms of services under the circumstances. To the extent your school is doing a lot less than this, its behavior may not be excused by the force majeure clause. The other clause that is relevant is the dispute resolution provision. Does it point to arbitration or to litigation? Litigation is very cumbersome and costly, for you and for the school; threat of litigation is an extreme option, but if you are so upset as to be wanting to withdraw your student right now, then maybe it would motivate administrators to pay attention to the issues.