About Donald H.
Donald H. Sienkiewicz trained first as an economist and later turned his attention to the law. He earned a B.A. in Economics and a degree in Environmental Policy from Boston University in 1990, then returned to school to complete his J.D. at Northeastern University in 1999. The combination of policy, economics and law shapes how he approaches client matters.
He began his legal career in private practice in the early 2000s. In 2003 he joined Goodwin Procter LLP as an associate. Two years later he moved to Rath, Young & Pignatelli P.A., where he continued to develop his practice. In 2009 he opened his own practice, Estate Preservation & Planning Law Office, and has led that firm since then.
Sienkiewicz is licensed to practice in both Massachusetts and New Hampshire. He has been active in the New Hampshire Bar Association, maintaining membership in its Estate Planning Section since 2006. That ongoing participation keeps him engaged with developments in state probate rules, tax considerations for estates, and practice issues that affect clients and fellow attorneys.
Throughout his career he has focused on matters that affect individuals and families as they plan for the future. His work covers estate planning, probate administration and related counseling. He advises clients on wills, trusts, powers of attorney and strategies to manage probate exposure. He approaches these matters with attention to practical details and the financial implications for clients and their heirs.
Colleagues describe him as someone who prefers clear explanations and practical solutions over legalese. He balances technical legal tasks, such as drafting trust instruments, with client-facing conversations about intergenerational planning and asset management. That balance is reflected in the steady client base his office has served since its founding.
He maintains an active small-firm practice through Estate Preservation & Planning Law Office. His work spans routine estate documents to probate administration in both Massachusetts and New Hampshire. He currently focuses on estate planning, probate administration and related elder-law matters.
