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Gary J. Siller



909 Fannin Street
Suite 2300
Houston, TX 77010
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Fax: 832.397.3512
J.D., cum laude, University of Houston Law Center, Houston, Texas, 1984, Order of the Coif; Order of the Barons; Houston Law Review, Associate Editor, 1983-84
B.B.A., with Honors, The University of Texas at Austin, Austin, Texas, 1981, Graduated in the top 1% from School of Business
State Bar Licenses
Court Admissions
U.S. District Ct., S.D. of Texas
Supreme Court of Texas

Gary J. Siller


Gary J. Siller is a board certified trial attorney who maintains a commercial litigation practice with a focus on health care and tax controversy. Gary's focus is also representing a significant South American clientele in a wide range of corporate and litigation matters. He is also a CPA and former founder and owner of two successful small businesses. He possesses broad business knowledge and financial proficiency. Based on his broad experience, he brings a creative and business-like approach to handling disputes of all nature.

Gary's health care practice includes representation of health care providers and medical products manufacturers and distributers in all aspects of their litigation needs. It also includes the representation of medical providers' and payers' disputes against insurance companies and the defense of RAC audits as well as the defense of claims against health care providers by the federal and state Offices of the Inspector General.

His tax controversy practice spans a broad range. He represents both companies and individuals in tax audits as well as a wide variety of matters before the IRS and in Federal Tax Court. His tax controversy practice includes disputes involving federal income tax, sales tax, trust fund recovery penalties, independent contractor vs. employee, innocent spouse and the reporting of foreign assets in various other related tax matters.

His practice also includes the representation of individuals and companies in business-related litigation, fiduciary and estate litigation and the investigation and pursuit of claims involving employee theft.

Gary also has a long history of representing accountants in accounting malpractice cases. He has successfully defended over 70 accounting malpractice cases in a broad range of disputes including matters related to audits, reviews, compilations, special engagement tax matters and securities claims.

Over Gary's career, he has handled and tried cases in a variety of areas. These include the defense of professional malpractice claims (including medical malpractice), insurance coverage disputes, insurance agent and broker malpractice claims, and employment litigation, including defense of class action employment cases brought by the EEOC. Although not presently Gary's focus, he has also handled and tried numerous personal injury cases, particularly in the area of oil field accidents. Mr. Siller is very familiar with most types of insurance coverages.

As a result of Gary's very broad commercial and litigation experiences, he also serves as outside general counsel for several of his clients serving their day to day needs.

He also maintains a significant South American clientele, which he represents in both litigation and non-litigation matters. This representation includes the handling of a variety of general corporate matters as well as providing general tax (domestic and international) advice, due diligence and the handling of negotiations in a variety of circumstances. Gary has been active in assisting clients in a variety of international dealings including the creation of entities all over the world.

Gary also occasionally represents celebrities, including professional athletes.

Gary Siller is Board Certified in Personal Injury Trial Law by the Texas Board of Legal Specialization. He is also a Certified Public Accountant in the State of Texas.


  • Defended a large E&P company in a four week trial involving both a death and personal injury in South Texas.
  • Successfully represented a mid-size accounting firm in a month-long trial on claims alleging accounting malpractice brought by an investment banking firm and individual investors on an alleged failed audit.
  • As lead counsel, defended a claim in excess of $75 million against an insurance brokerage firm. Gary managed a team of five lawyers defending this claim.
  • Defended a publicly traded company involved in a Sarbanes-Oxley whistleblower complaint.
  • Representation of a large medical products distributor in a claim before the state office of the Inspector General.
  • Represented an ex-NBA basketball star in his dispute with the National Basketball Association and the Dallas Mavericks.
  • Represented a Houston Texans football player in his lawsuit against the City of Houston involving a taser incident.


  • Handling IRS Appeals and Other Tax Controversies, Strasburger Tax Symposium, Houston (August 2013)
  • IRS Enforcement Update, Strasburger Annual Tax Symposium (August 2011)
  • Protecting You and Your Clients from Litigation, American Association of Attorneys-CPA 2009 Southwest Regional Education Conference (January 2009)
  • Estate and Tax Planning for Retirement Benefits, Strasburger Tax Symposium (August 2008)
  • The new 'margin tax' on business entities in Texas presented to Certified Public Accountants, Strasburger Tax Symposium (August 2007)
  • Accounting Malpractice - A Litigator's View, Strasburger Annual Tax Symposium (August 2006)
  • Avoiding and Reducing the Risk of Accounting Malpractice, Interstate Insurance Company for their accountant insureds
  • Texas Indemnity Law Update and Related Insurance Issues, Independent insurance agents of Houston


  • HIPAA Omnibus Rule Imposes New Standards for Handling Potential Breaches of Health Information, Strasburger Health Industries Online (September 2013)
  • Anti Trust Violations - The Application of the Per Se Rule to Maximum Price Fixing Within Professions, Arizona v. Maricopa County Medical Society, 20 Houston Law Review 1239


Rated AV Preeminent by Martindale-Hubble
Houston Bar Association, Texas Society of Certified Public Accountants, Houston CPA Society, Board of Directors, Healthcare Committee
Board of Directors, Tax Committee, National Association of Corporate Directors, Turnaround Management Association, American Diabetes Association, Board of Directors
Chair, Golf Classic and Major Sponsors Dinner Committee, Ducks Unlimited, Life Sponsor
Practice Areas
Areas of Emphasis
General Tax Planning