First question: Health insurance is not a freebie. It is risk pooling, i.e. its function is to spread the risk of medical treatment out over a group of people. The characteristics of the members of the group are what determine the risk, the costs and the premiums. Covering preexisting conditions raises the sickness level, and thus the medical expense, of the insurance pool. Premiums rise. They can rise dramatically. Through shouldering known expense, people who are well pay not for actuarial risk but for the treatment of people who are not. The system becomes an income redistribution mechanism.
Second question: Americans with low incomes receive subsidies through PPACA (Obamacare). The premiums of policies under this new law are staggering, and the coverage is poor, due to a number of those known treatment expenses one of which is mentioned in the first paragraph above. If a taxpayer reports an income of less than certain amounts, however, he may be given federal payment of part or in some cases all of the premium for a low-grade policy. These subsidies are another cause of PPACA's high premiums and low quality of insurance, but nominal insurance coverage is available to those who otherwise might not be able to afford it. If you have no income you should qualify for a policy paid for by others, but you must get it through one of the exchanges.