Sigmund J. Roos

  • Partner


Boston, MA





Sigmund J. Roos
Rated by Super Lawyers

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Before founding Block & Roos, LLP with Jessica Block, Sig Roos was a partner in one of the country's largest law firms. Having worked in that setting as well as in a fast-paced, mid-sized firm specializing in commercial litigation, Sig appreciates the demands of complex litigation. He now applies the skills honed during his 30 year career toward handling a wide range of matters including:

  • Business litigation
  • Complex commercial litigation
  • Real estate syndication litigation
  • Commercial collections
  • Enforcement of out-of-state and foreign judgments 
  • Partnership, trust, and close corporation disputes
  • Securities litigation
  • Shareholder disputes
  • Professional licensure and misconduct

Sig's skills as a negotiator, his facility with the law and the rules of procedure, and his no-nonsense approach in court have achieved results that have gained him the respect of clients, judges, and attorneys throughout Massachusetts.

Sig's roster of clients includes several national law firms, a Fortune 500 corporation, and one of the country's leading real estate investment firms. His work for these companies ranges from partnership and shareholder actions to non-competition and general contract disputes, to consumer disputes and collection matters. He also has had extensive experience representing attorneys, physicians, nurses, veterinarians, research faculty, and other professionals in licensing and research integrity matters.

In 2008 Sig Roos was named one of the Top 100 Boston Lawyers by Boston Magazine and has been named a Super Lawyer each year since 2005 by Boston Magazine. The “Super Lawyer” honor is bestowed upon the top 5% of lawyers in the state who have achieved a high degree of peer recognition and professional achievement.

Until recently, Sig served as the Chair of the Hampshire College Board of Trustees and is currently, a member of the Board of the Concord Art Association in Concord, MA and president of a family foundation. For 8 years, Sig spent a week each year volunteering his time as a teaching team member at the Harvard Law School Trial Advocacy Workshop.

Areas Of Practice

  • Business Litigation
  • Medical Disciplinary Proceedings
  • Noncompetition
  • Creditors Rights
  • Administrative
  • Alternative Dispute Resolution
  • Professional Licensure and Misconduct

Bar Admissions

  • Massachusetts, 1983
  • U.S. District Court District of Massachusetts, 1984
  • U.S. Court of Appeals 1st Circuit, 1986
  • U.S. District Court Northern District of Texas, 1986
  • U.S. Bankruptcy Court Southern District of Texas, 1984


  • Northeastern University School of Law, Boston, Massachusetts
    • J.D. - 1983
  • Brown University, Providence, Rhode Island
    • M.A. - 1980
    • Major: American Civilization
  • Hampshire College, Amherst, MA 01002
    • B.A. - 1977
    • Major: Legal Studies and American Civilization