31 C.F.R. § 35.8
(b) Violation. Treasury will consider a State or Territory to have used funds to offset a reduction in net tax revenue if, during a reporting year:
(4) Consideration of other changes. The aggregate amount of measured or predicted reductions in tax revenue caused by covered changes is greater than the sum of the following, in each case, as calculated for the reporting year:
(ii) Reductions in spending, up to the amount of the State's or Territory's net reduction in total spending, that are in:
(c) Amount and revenue reduction cap. If a State or Territory is considered to be in violation pursuant to paragraph (b) of this section, the amount used in violation of paragraph (a) of this section is equal to the lesser of: