A multi-year contract means a contract for the purchase of supplies or services for more than 1, but not more than 5, program years. Such contracts are issued under specific congressional authority for specific programs. A multi-year contract may provide that performance under the contract during the second and subsequent years of the contract is contingent upon the appropriation of funds, and (if it does so provide) may provide for a cancellation payment to be made to the contractor if appropriations are not made. The key distinguishing difference between multi-year contracts and multiple year contracts is that multi-year contracts buy more than 1 year of requirement (of a product or service) without establishing and having to exercise an option for each program year after the first.