A document published by the Internal Revenue Service (IRS) that details the rules covering how gains from an installment sale are to be reported. Taxpayers who sell property using the installment method receive at least one payment in a later tax period, and may report part of the gain from the sale when the payment is received. When reporting gains using Form 6252 (Installment Sale Income), the taxpayer indicates the income from the gain on the sale as well as any interest received during the year in which payment is given.

Property can include real estate but does not include inventory; people who regularly sell personal property ("dealers") are not permitted to use the installment method. Taxpayers do not have to use the installment method when selling property, and can choose to report all of the gain in the year of the actual sale. The installment method cannot be used if a loss was taken on the sale. If a loss was taken on an installment sale it can only be deducted in the year that the property was sold.