The IRS Restructuring and Reform Act of 1998 prompted the most comprehensive reorganization and modernization of IRS in nearly half a century. The IRS reorganized itself to closely resemble the private sector model of organizing around customers with similar needs.

To support its structure and ensure accountability, the IRS is divided into three commissioner-level organizations:

Commissioner

Specialized IRS units report directly to the Commissioner’s office. The IRS Chief Counsel also reports to the Treasury General Counsel on certain matters.

• Commissioner, Internal Revenue — Douglas Shulman
• Chief of Staff — Jonathan M. Davis
• IRS Chief Counsel — William J. Wilkins
• Appeals — Diane Ryan, Chief
• Taxpayer Advocate Service — Nina E. Olson, National Taxpayer Advocate
• Equity, Diversity and Inclusion — Debra Chew, Executive Director 
• Research, Analysis and Statistics — Patricia McGuire, Acting Director
• Communications and Liaison — Frank Keith, Chief

Deputy Commissioner for Services and Enforcement

The Deputy Commissioner reports directly to the Commissioner and oversees the four primary operating divisions and other service and enforcement functions:

• Deputy Commissioner for Services and Enforcement — Steven T. Miller
• Wage and Investment Division — Richard E. Byrd, Jr., Commissioner
• Large and Mid-Size Business Division — Heather Maloy, Commissioner
• Small Business/Self Employed Division — Christopher Wagner, Commissioner
• Tax Exempt and Government Entities Division — Sarah Hall Ingram, Commissioner
• Criminal Investigation — Eileen C. Mayer, Chief
• Office of Professional Responsibility — Karen L. Hawkins, Director 
• Whistleblower Office —  Stephen A. Whitlock, Director

Deputy Commissioner for Operations Support

The Deputy Commissioner reports directly to the Commissioner and oversees the integrated IRS support functions, facilitating economy of scale efficiencies and better business practices:

• Deputy Commissioner for Operations Support — Mark Ernst
• Chief Technology Officer — Terence V. Milholland
• Agency-Wide Shared Services — Dave Grant, Chief
• Human Capital Officer — James P. Falcone, Chief
• Chief Financial Officer — Alison Doone, Chief
• Office of Privacy, Information Protection and Data Security — Deborah Gascard Wolf, Director

Organization Chart

See the basic structure of today's IRS in this picture of the IRS Organization Chart. 

At-a-Glance: IRS Divisions and Principal Offices

Get an overview of the four primary operating divisions and the other principal offices in the IRS organization.