Mark Lennon is a tax attorney assists clients with Employee Retirement Income Security Act of 1974 (ERISA) issues in numerous types of corporate transactions, including mergers, acquisitions, add-ons, divestitures, carve-outs and joint ventures. Mr. Lennon guides clients through complex employee benefits matters, including controlled group considerations, 401(k) plan design and compliance, health and welfare plans, retirement plans and Affordable Care Act issues. His experience also includes identifying and resolving post-transaction issues and preparing IRS and U.S. Department of Labor voluntary compliance filings.

Previously, Mr. Lennon gained valuable experience as an associate in the Chicago office of Kirkland & Ellis and a tax consultant in the Chicago office of Ernst & Young.


  • Loyola University Chicago School of Law, J.D., magna cum laude
  • Marquette University, B.S., cum laude
Bar Admissions/Licenses
  • Tennessee
  • Illinois
Honors & Awards
  • The Best Lawyers in America guide, Ones to Watch, Employee Benefits (ERISA) Law, 2022, 2023