William McGarrity

William G. McGarrity is a Tax Controversy partner in Mayer Brown’s Chicago office. Will represents clients in all stages of federal tax controversies, including examination, administrative appeals, and litigation.

His work encompasses issues related to transfer pricing, cost sharing agreements, valuation, treatment of goodwill and going concern value, debt-equity characterization, economic substance, and administrative procedure as applied to the IRS regulatory process.

Litigation and Administrative Proceedings: Will has experience litigating major corporate cases in the areas of transfer pricing and debt-equity characterization. Notable cases include Altera (145 T.C. No. 3, unanimous Tax Court opinion invalidating stock-based compensation rule in cost sharing regulations), the Tyco debt-equity litigation (fifteen consolidated cases, over $9 billion in interest deductions implicated in the litigation and later-cycle years, settled prior to trial for 5% of the amount at issue), and the Guidant/Boston Scientific transfer pricing litigation (section 482 adjustments as well as section 367(a) and (d) adjustments on outbound transfer).

Throughout these litigation matters, Will has worked extensively with leading experts in the fields of economics, finance, and forensic accounting.

Transfer Pricing and Tax Advice: Will’s experience also includes advising clients on transfer pricing documentation and structuring, particularly with respect to intangible property (both discrete IP as well as novel issues related to soft intangibles like goodwill and going concern value). In this planning work, Will draws on his controversy experience to anticipate potential legal and expert arguments.

Education :

• Harvard Law School, JD, cum laude
• University of Cambridge, LLM
• University of Michigan, BBA, with high distinction

Admissions :

• Illinois
• US Tax Court
• US Court of Federal Claims
• US Court of Appeals for the Ninth Circuit

Experience :

• Altera Corporation v. Commissioner of Internal Revenue, 145 T.C. No. 3 (2015), 15-0 reviewed Tax Court opinion, holding invalid section 482 regulations requiring cost sharing participants to share amounts attributable to stock-based compensation.
• Cardiac Pacemakers, Inc. v. Commissioner of Internal Revenue, T.C. Docket No. 5502-12 (IRC § 482 reallocations).
• Guidant LLC v. Commissioner of Internal Revenue, T.C. Docket No. 5989-11 (IRC § 482 reallocations).
• Tyco Electronics Corp., as successor in interest to Tycom Simplex Holdings, Inc. & Subsidiaries v. Commissioner of Internal Revenue, T.C. Docket No. 16651-13 (debt-equity characterization).
• Tyco Electronics Corp., formerly known as AMP, Inc., & Subsidiaries v. Commissioner of Internal Revenue, T.C. Docket No. 16654-13 (debt-equity characterization).
• Tyco Electronics Corp., as successor in interest to TSSL Holding Corp. & Subsidiaries v. Commissioner of Internal Revenue, T.C. Docket No. 16655-13 (debt-equity characterization).
• ADT Holdings, Inc. v. Commissioner of Internal Revenue, T.C. Docket No. 16656-13 (Withholding Tax).