The remaining 45% of health care funding comes from insurance premiums paid by the public, for which companies compete on price, though the variation between the various competing insurers is only about 5%. However, insurance companies are free to sell additional policies to provide coverage beyond the national minimum. These policies do not receive funding from the equalization pool, but cover additional treatments, such as dental procedures and physiotherapy, which are not paid for by the mandatory policy.
Based on the principle of solidarity and compulsory membership, the calculation of fees differs from private health insurance in that it does not depend on personal health or health criteria like age or sex, but is connected to one's personal income by a fixed percentage. The aim is to cover the risk of high cost from illness that an individual can not bear alone.