Diane Ryan

Diane Ryan

Retired Of Counsel, Tax
With more than 35 years of experience at the Internal Revenue Service, former national chief of appeals Diane Ryan has handled complex procedural issues; international tax issues, including cost-sharing transactions; taxation of hybrid instruments; alternative dispute resolution methodologies; and appellate resolution of major tax cases.


Ms. Ryan joined Skadden, Arps in 2011 as an of counsel in the Chicago office. At the Internal Revenue Service she was responsible for providing leadership to the independent administrative dispute resolution forum for tax controversies (with more than 2,000 employees and relevant to 159 million taxpayers and business entities). She also served as director of technical services, where she led three nationwide critical technical functions of Appeals (Technical Guidance, International, and Tax Policy and Procedure). Previously, she worked as director of technical guidance at the Appeals Division.

Her work with the IRS was recognized with various awards, including the Commissioner Outstanding Award, the Commissioner LMSB Award and the National Chief’s Award.

Ms. Ryan also worked in private practice, where she focused on establishing and pursuing bankruptcy/receivership claims in Asia and other foreign jurisdictions for emerging market investment firms.

In addition to her tax practice, she has held several teaching positions, including at St. Louis University Law School, Southwestern Illinois College and Southern Illinois University Edwardsville.



  • J.D., St. Louis University Law School, 1991 (magna cum laude)
  • M.B.A., Southern Illinois University Edwardsville, 1980
  • B.S., Southern Illinois University Edwardsville, 1978 (high honors)


  • Illinois


  • Certified Public Accountant (1981)

Diane Ryan