Ask HN: Leap to entrepreneur: How to do medical insurance?

I am a married 30-something American with 2 young children at home. Recently, I have been in committed talks to go the route of an entrepreneurial path instead of working for a large (and relatively secure) corporation. My main concern is that if someone is sick, I want them to be able to go to the doctor without bankrupting my account. I understand that choosing to be an entrepreneur has risks associated with it and finances are a relatively large assumption. I wish to mitigate the health area as much as possible, so I am seeking advice about how others at HN have accomplished this feat. Thanks for your time.