An installment contract is a single contract that is completed by a series of performances–such as payments, performances of a service, or delivery of goods–rather than being performed all at one time. Installment contracts can provide that installments are to be performed by either one or both parties.
An installment sale has the following primary disadvantages: The sold assets will not receive stepped-up basis in the event of your death.
About Form 9465, Installment Agreement Request. Internal Revenue Service.