Four primary IRS Divisions at-a-glance: Large Business and International Small Business/Self-Employed Tax-Exempt and Government Entities Wage and Investment Other principal offices: Appeals Communications and Liaison Criminal Investigation Equity, Diversity and Inclusion Office of Chief Counsel Office of Professional Responsibility (OPR) Office of Promoter Investigations Privacy, Governmental Liaison and Disclosure Procurement Return Preparer Office Taxpayer Experience Office Whistleblower Office