I think we need to expand the pool of preexisting conditions to better reflect their impact on health care costs. Currently we define preexisting conditions as disease states but it should include behaviors that lead to health issues. We should then start charging those people more now — why should they be a future burden on society?
Smokers and and anyone who has lived in the same housing as smokers — high lung and other cancer risk.
Sun bathers and people with deep tans — high skin cancer risks. Also, redheads and fair skinned individuals.
Red meat eaters — high colon cancer risk.
People who attended rock concerts — high hearing loss risk.
Coal miners — what more needs to be said.
Farmers — high exposure to pesticides and other agricultural chemicals. High cancer risk.
Overweight or sedentary individuals — high coronary and heart disease risk.
Outdoorsmen and hunters — high risk of exposure to tick-born diseases. High risk of accidental gun injuries. Risk of falls from hunting stands.
Drivers — high risk of multiple injuries from being on roads. Same for bicyclists and pedestrians.
Sports enthusiasts — high risk of knee, back, head, and other injuries.
Vicious dog owners — high risk for other people to be severely injured.
Many more could be added. The point is, a lot of behaviors affect health care spending just as much as current disease state, premiums should be adjusted to reflect the risk and insurance companies should be required to deny coverage for people who follow any of these behaviors if they choose to deny coverage for current or past disease state.