Ann MacDonald O’Sullivan

Senior Partner

(978) 689-8822
Ann MacDonald O'Sullivan, LCW CPAs Senior Partner

Professional Summary

Ann’s prior firm, O’Sullivan & Company, merged with LCW CPAs in 2022, to offer expanded services to our clients as they navigate the ever-changing tax laws. As Senior Partner, Ann’s role at LCW CPAs is focused on tax planning, providing creative and strategic solutions, and delivering timely and accurate tax preparation services. Ann enjoys helping clients make informed, long-term decisions based on economic value.


  • Bentley University, Bachelor of Science in Accountancy with High Honors, May, 1982

Professional Designations

  • Certified Public Accountant (CPA)

Professional Associations, Memberships, & Community Involvement

  • Member, American Institute of Certified Public Accountants (AICPA)
  • Member, Massachusetts Society of Certified Public Accountants (MSCPA)
  • Treasurer, New England Equine Rescue – North, Inc. (NEER North)
  • Former member – West Newbury Board of Selectmen – 2 terms
  • Former treasurer – Pentucket Education Foundation
  • West Newbury Youth League
  • West Newbury PTO
  • Friends of West Newbury Council on Aging
  • Former Big Sister – Big Brothers/Big Sisters

Honors, Awards, & Recognition

  • Andover Community Trust – Service award


When she is not working, Ann enjoys reading, gardening, traveling, and giving tours at NEER North.