Skip to main content

William E. Keenen focuses his practice on trust and estate matters, particularly estate planning for high-net-worth individuals and their families. He is experienced in the areas of multigenerational wealth transfer, life insurance, post-mortem tax and pre-immigration planning, and cross-border investment. William’s practice also includes the negotiation and preparation of prenuptial and postnuptial agreements.

In addition, William counsels clients with respect to the day-to-day administration of trusts and estates, and assists corporate and individual fiduciaries as well as beneficiaries in litigated trust and probate matters.

William has represented clients in tax controversies and other tax matters before the Internal Revenue Service (IRS), including matters involving U.S. income, estate, gift and generation-skipping transfer (GST) tax, and offshore voluntary disclosure issues. He has also assisted clients with the formation and operation of private foundations.

William has written about and lectured on various transfer tax topics affecting high-net-worth individuals and their families, including in the areas of allocations of GST exemption and the application of the U.S. estate and gift tax law to transfers of property by citizens and non-citizens of the U.S.


  • Multigenerational wealth transfer planning
  • Estate, gift and GST tax matters and controversies before the IRS
  • International estate planning
  • Prenuptial and postnuptial agreements
  • Trust and estate administration and litigation
  • Business succession planning
  • Private foundations


Recognition & Leadership

  • Listed, The Best Lawyers in America, "Ones to Watch," Tax Law; Trusts and Estates, 2021
  • Listed, South Florida Legal Guide, "Top Up-and-Comer," 2020
  • Trust and Estate Practitioner (TEP), Society of Trust and Estate Practitioners (STEP), Miami Branch, 2018-Present (Technician Member, 2014-2018)
  • Member, Brickell Avenue Literary Society, 2018-Present
  • Member, Young Professionals (formerly the Upper Room), Miami City Ballet, 2017-Present
  • Member, Tax Section of The Florida Bar, 2012-Present
  • Event Chair, Don Q Crash the Gala, Miami City Ballet, 2019-2020
  • Member, 2020 Gala Committee, Miami City Ballet, 2019-2020
  • Graduate (LM Class 40), Leadership Miami, Greater Miami Chamber of Commerce, 2018-2019
  • Member, The Grand Finale Steering Committee, Miami City Ballet, 2018-2019
  • Graduate (Class II), Florida Fellows Institute of the American College of Trust and Estate Counsel (ACTEC), 2017
  • Participant, OutLeadership’s OutNEXT Summit, 2016
  • Mentor, Big Brothers Big Sisters of Greater Miami, School to Work Program, 2014-2016
  • Tax Law Clerk, Legal Services of Greater Miami, Inc., 2012


  • LL.M., Taxation, University of Miami School of Law
    • Recipient, Dean's Certificate of Achievement Award, Taxation of Business Entities: Partnership
    • Recipient, Merit Scholarship
  • J.D., cum laude, University of Miami School of Law
    • Recipient, C.A.L.I. Excellence for the Future Award for Family Law
    • Recipient, Dean's Outstanding Public Interest Scholarship
  • B.S., summa cum laude, Sam Houston State University
  • Florida
  • District of Columbia
  • Texas
  • U.S. Tax Court