Actually there's at least 2 incentives: 1) even with insurance coverage you have a deductible, and unless you have a year with a lot of doctor visits or procedures, you're probably going to end up paying almost everything out of pocket, 2) higher medical bills drive insurance costs, if you can get lower bills you can reduce your insurance costs (not even negotiating with the insurance, but just simply switching to a different/cheaper plan with lower coverage).