A deductible which is not set at a fixed amount but rather varies according to income. A family is usually required to spend all (a spend-down) oi a set percentage of their income above some base amount (for example, all Cr 25 percent of any income over $5,000) as deductible before a member can receive medical care benefits. There may be a maximum amount on the deductible. The sliding scale concept can also be applied to coinsurance and copayments.