The Treasury Department and the IRS have issued guidance (Notice 2018-28) for computing the business interest expense limitation under the Tax Cuts and Jobs Act. In general, the new tax law imposes a limitation on deductions for business interest incurred by certain large businesses. For most large businesses, business interest expense is limited to any business interest income plus 30% of adjusted taxable income. These new limitations blunt the effects of the interest expense tax shield, which increases the cost of debt.