Copayment  A copayment or copay is a fixed amount for a covered service, paid by a patient to the provider of service before receiving the service. It may be defined in an insurance policy and paid by an insured person each time a medical service is accessed. It is technically a form of coinsurance, but is defined differently in health insurance where a coinsurance is a percentage payment after the deductible up to a certain limit. It must be paid before any policy benefit is payable by an insurance company. Copayments do not usually contribute towards any policy out-of-pocket maxima whereas coinsurance payments do. Insurance companies use copayments to share health care costs to prevent moral hazard. It may be a small portion of the actual cost of the medical service but is meant to deter people from seeking medical care that may not be necessary (e.g., an infection by the common cold). In health systems with prices below the market clearing level in which waiting lists act as rationing tools, copayment can serve to reduce the welfare cost of waiting lists. However, a copay may also discourage people from seeking necessary medical care and higher copays may result in non-use of essential medical services and prescriptions, thus rendering someone who is insured effectively uninsured because they are unable to pay higher copays. Thus, there is a balance to be achieved: a high enough copay to deter unneeded expenses but low enough to not render the insurance useless. The German healthcare system had introduced copayments in the late 1990s in an attempt to prevent overutilization and control costs. For example, Techniker Krankenkasse-insured members above 18 years pay the copayments costs for some medicines, therapeutic measures and appliances such as physiotherapy and hearing aids up to the limit of 2% of the family's annual gross income. For chronically ill patients, the co-payment limit is 1% including any dependant living in their home. The average length of hospital stay in Germany has decreased in recent years from 14 days to 9 days, still considerably longer than average stays in the U.S. (5 to 6 days). The difference is partly driven by the fact that hospital reimbursement is chiefly a function of the number of hospital days as opposed to procedures or the patient's diagnosis. Drug costs have increased substantially, rising nearly 60% from 1991 through 2005. Despite attempts to contain costs, overall health care expenditures rose to 10.7% of GDP in 2005, comparable to other western European nations, but substantially less than that spent in the U.S. (nearly 16% of GDP).