The Department of the Treasury, Internal Revenue Service (IRS), on behalf of the Cross Border Activities (CBA) Practice Area within the Large Business & International Division, is seeking information from industry on the capability to deliver a software solution that enables IRS personnel to model and analyze the application of international tax provisions under the Tax Cuts & Jobs Act (TCJA) of 2017, the One Big Beautiful Bill Act of 2025 (OB3), and pre-existing tax law. The scope includes not only development and delivery of the tool, but also comprehensive support services such as user training, ongoing maintenance, and eventual integration of the solution into IRS operations.