Derek W. Kaczmarek is partner and co-founder of Kaczmarek & Jojola, a tax litigation firm. His practice includes tax litigation, tax audits, and tax collection. As a tax controversy attorney, he represents individuals, businesses, trusts and estates against the I.R.S. and state/local taxing authorities.

The firm currently represents clients in 35+ states and numerous foreign countries.

The Tax Section of the State Bar of Arizona elected Mr. Kaczmarek as the chair in 2018. The State Bar of Arizona’s Board of Legal Specialization also recognizes Mr. Kaczmarek as a certified tax law specialist. Mr. Kaczmarek also serves on the State Bar’s Board of Legal Certification.

Mr. Kaczmarek began his tax controversy career as a trial attorney with the I.R.S. in Las Vegas, Nevada in 2005. He ended his government service in 2012 as a senior trial attorney with the I.R.S. in Phoenix, Arizona. During that time, he represented the I.R.S. in hundreds of cases before the United States Tax Court. He served as lead counsel in more than forty U.S. Tax Court trials. He also advised I.R.S. revenue agents and revenue officers in issues ranging from development of criminal cases, seizure of property (including personal residences), conducting a tax fraud audit, innocent spouse cases and international tax issues.

Mr. Kaczmarek discretely and aggressively represents his clients, effectively using his experience as a former government attorney as well as his understanding of IRS and U.S. Tax Court practices and procedures.


  • New York University School of Law – LL.M. (Taxation), 2005
  • Indiana University School of Law, Bloomington – J.D. (Cum Laude), 2003.


  • State Bar of Arizona, Tax Section, elected Chairman, 2018 – 2019
  • State Bar of Arizona, Tax Section, elected Chair-Elect, 2017 – 2018
  • State Bar of Arizona, Tax Section, elected Vice-Chair, 2016 – 2017
  • State Bar of Arizona, Tax Section, elected Chief Budget Officer, 2015 – 2016
  • State Bar of Arizona, Tax Section, elected Secretary, 2014 – 2015
  • State Bar of Arizona, Tax Section, elected Member-at-Large, 2012 – 2014
  • Western States Bar Association, Arizona Representative, 2013 – present
  • Scottsdale Bar Association, elected member Board of Directors, 2013 – 2014

Published Cases

  • Norma L. Slone, Transferee, et al. v. Commissioner, T.C. Memo. 2016-115 (U.S. Tax Court 2016)
  • David L. Bruner v. Commissioner, T.C. Memo. 2018-10 (U.S. Tax Court 2018)
  • Edward Anthony & Maureen Helena Purvis v. Commissioner, T.C. Memo. 2020-13 (U.S. Tax Court 2020)


  • Super Lawyers: Top Rated Tax Lawyer
  • Best Lawyers in America
  • Martindale-Hubbell, AV Peer Rating
  • State Bar of Arizona, Certified Specialist – Tax Law
  • I.R.S. Office of Chief Counsel, Cube Award (litigation of national significance)
  • I.R.S. Office of Chief Counsel, SB/SE, Litigation Award

Derek W. Kaczmarek

Rated by Super Lawyers

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