Health insurance companies do not receive from the package of money collected on the health insurance contributions the same amount for every insured. It depends on the factors of age, gender and economic category, and if the patient has some of the serious diagnosis which requires administering of expensive pharmaceuticals. The money is reallocated among health insurance companies by means of cost risk index for health care. According to health insurance company Dôvera the preciseness of estimation of the amount of the cost according to the cost risk index differs from the real cost by about 20 %. Until the last year was this estimation according to health insurance company much less precise, it was about 4 %.