Maintenance health care cost reimbursement can be insurance, but it has to be based on actuarial science as it applies to health care. Obamacare never did that since the law was to cover pre-existing conditions. The best example is for a person to be able to purchase fire insurance for their house after it burns or auto insurance after the wreck.
Special pools to cover the uninsurable are the answer, not forcing the healthy to pay for the sick.