According to the principle of risk equivalence, individual payments and premiums under private insurance contracts must always be calculated as a function of the applicant's specific risk. Consequently, the applicant must disclose whatever he or she knows about his/her state of health, since only in this way can the individual risk of disease be calculated.

In contrast to this concept of risk equivalence, statutory health insuranc follows the principle of solidarity. According to this principle, the assessment of contributions and thus the entitlement to benefits of the insured is not based on their individual pre-existing conditions and health risk factors and thus on the insurance risk, but on their individual financial capacity. With lower incomes, health insurance contributions are also lower; with high incomes, contributions are correspondingly higher; however, all insured persons, regardless of income, have the same entitlement to medical services.