Go read this story, and in particular pay attention to this paragraph, which talks about a hypothetical attempt to pay out of pocket for care denied by the insurer:

But we soon learned another sinister result of hyper-privatization of health insurance—even if we had the excessive means to pay the hundreds of thousands of dollars out of pocket, the hospital would not accept the funds. Why? The industry is such that not only do insurance companies deny 51% of claims, they have enacted policies forbidding people from paying for the critical medication they need out of pocket, lest the insurance company lose control and revenue. “Either you pay us, or you pay no one,” is a line you’d expect out of a mafia handbook—not out of a health provider. This is not health insurance, this is health exploitation.

Single payer now.