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About me

My practice focuses on Tax Exempt Non-Profit Organizations and the people whose philanthropy makes them possible.  As general counsel for many nonprofits, I am familiar with the compensation, lobbying and political activity restrictions under which they labor, and the legal and ethical ways in which to complyt with these.  Much of my work concerns audits on Tax Exempt Non-Profit Organizations by the Internal Revenue Service and internal disputes among members, officers and directors/Trustees.


Estate Planning is important for everyone, but especially those with estates large enough to be taxable.  As development counsel to several large nonprofit organizations, I am familiar with both the needs of donors and the institutions they support when it comes to developing and implementing an estate plan.


My motto is "Seek Creativity," and that is why I suggest you visit the Art Gallery at my firm's website,, where over 25 images that I have drawn and painted over the past 15 years are on display.


Practice areas


  1. Tax: 60%
    44 years, 1 thousand cases
  2. Estate Planning: 40%



Hourly ($400/hour)

Payment types:


Attorney endorsements

1 total 

Are you an attorney? Endorse this lawyer

  • Steven A Widdes

    I endorse this lawyer's work. Mark is a fine attorney and is well respected in the estate planning community. He not only is recognized for his planning but has a unique understanding of complex charitable tax and the practical aspects entailed with such philanthropic matters. He is also an excellent contributor to the nonprofit community by giving so much of his time and efforts.


    Steven Widdes Estate Planning Attorney
    Relationship: Fellow lawyer in community

Contact info

Weinberg & Jacobs Llp
11300 Rockville Pk Ste 1200
Rockville, MD, 20852

11300 Rockville Pike Ste 1200
Rockville, MD, 20852-3040

Ste 1200
11300 Rockville Pike
Rockville, MD, 20852-3003



DCActive 197105/24/2015
We have not found any instances of professional misconduct for this lawyer.
Avvo contributions
Legal answers
Award nameGrantorDate granted
Washington Super LawyerWashington Super Lawyer Magazine2009
Maryland Super LawyerMaryland Super Lawyers Magazine2009
Work experience
TitleCompany nameDuration
Senior PartnerWeinberg &Jacobs, LLP1988 - Present
Sole PractitionerMark B. Weinberg, P.C.1985 - 1988
PartnerGolden Freda & Schraub1983 - 1985
Galley SlaveArent Fox Kintner Plotkin & Kahn1977 - 1983
Assistant Branch ChiefInterpretative Division, Office of the Chief Counsel, Internal Revenue Service1971 - 1977
Association namePosition nameDuration
American College of Trust and Estate CounselMember, Charitable Planning and Exempt Orgs. Committee2007 - Present
American Bar AssociationVice Chair, Charitable & EO Group, Trusts and Estates Div.2004 - 2006
American College of Trust and Estate CounselFellow2002 - Present
American College of Trust and Estate Counsel (Maryland chapter)Member2002 - Present
D.C. Estate Planning CouncilMember1985 - Present
American Bar AssociationCommittee Member-Exempt Organizations1972 - Present
Publication nameTitleDate
Taxation of ExemptsRelieving the Burdens of a Changing Government2008
School nameMajorDegreeGraduated
The Law School, University of ChicagoN/AJD1970
Arizona State UniversityHistoryBA, with Distinction1967
Speaking engagements
Conference nameTitleDate
Annual Meeting of Washington D.C. Metropolitan AreaHARD WON INSIGHTS INTO CHARITABLE ESTATE PLANNING2008