This is the statute that sets out the disposable income test used in bankruptcy. Many judges use the disposable income test as a tool in analyzing the Ability Test portion of Section 523(a)(15).
This is the text of 11 U.S.C. §1325(b)(2).
For purposes of this subsection, “disposable income” means income which is received by the debtor and which is not reasonably necessary to be expended–
(A) for the maintenance or support of the debtor or a dependent of the debtor; and
(B) if the debtor is engaged in business, for the payment of expenditures necessary for the continuation, preservation, and operation of such business.