It MAY be needed to calculate the Qualified Business Income Deduction. (199A)
"If a taxpayer has taxable income above the higher taxable income threshold and owns a business that is not a specified service trade or business, the QBI deductible amount for the business is subject to a limitation based on W-2 wages and/or capital (capital here is measured as the unadjusted basis of certain business assets) (Sec. 199A(b)(2)(B)). The deductible QBI amount for the business is equal to the lesser of (1) 20% of the business's QBI, or (2) the greater of: (a) 50% of the W-2 wages for the business, or (b) 25% of the W-2 wages plus 2.5% of the business's unadjusted basis in all qualified property. Thus, two alternative limitations under Sec. 199A(b)(2) may limit the deductible QBI amount for each business that is included in a taxpayer's combined QBI amount: (1) a pure 50% wage test, or (2) a combined 25% wage and capital test."
https://www.journalofaccountancy.com/issues/2018/may/sec-199a-deduction-for-qualified-business-incom...
