Karen F. Green


Green, Karen F.

Karen Green's practice concentrates on complex business litigation, including the defense of white-collar criminal and False Claims Act litigation. She has extensive experience representing companies in high-stakes government investigations and litigation alleging fraud, bribery, conspiracy and violations of federal statutes, including the Anti-kickback Statute, the Food Drug and Cosmetic Act, the Foreign Corrupt Practices Act, the Export Control Act and securities laws. At the request of corporate clients, she also has conducted numerous internal investigations of alleged wrongdoing and has advised their boards on compliance issues. Ms. Green has been selected as among the top investigations lawyers in the world, and has been consistently recognized by legal publications as a leader in litigation, including the defense of government and white collar criminal investigations and litigation. In 2014, she was selected as a 2015 Fellow of Harvard University's Advanced Leadership Initiative.

From 1993 to 1996, Ms. Green was the Deputy US Attorney for the federal District of Massachusetts. She supervised the investigation and prosecution of criminal cases and the litigation of civil cases on behalf of the United States. She also led the office's civil and criminal healthcare fraud enforcement program and served on the Department of Justice's National Health Care Fraud Working Group.

Ms. Green first joined legacy Hale and Dorr as a litigation associate in 1982. From 1984 through 1986, she served as an assistant US attorney in the Civil Division of the US Attorney's Office in Boston. She was appointed deputy chief of the Civil Division in June of 1986, and successfully obtained summary judgment on behalf of the EPA in a lawsuit compelling the cleanup of Boston Harbor. In January of 1987, Ms. Green returned to Hale and Dorr. She was elected to junior partnership in 1988, and to senior partnership in 1990. During the period from 2000 to 2007, Ms. Green served as vice chair and chair of Hale and Dorr's Litigation Department and as co-chair of WilmerHale's Litigation/Controversy Department. She also served as a member of the firm's Executive Committee.

In 1993, Massachusetts Governor William F. Weld appointed Ms. Green his chief of staff. She co-chaired governor-elect Weld's transition team for the Executive Office of Health and Human Services in late 1990 and early 1991.

Honors & Awards

  • Selected by peers for inclusion in the 2008-2016 editions of the Best Lawyers in America in the area of white-collar criminal defense
  • Selected as one of "Top Women of Law” by Massachusetts Lawyers Weekly in 2011 and 2015, and inducted into the publication's Circle of Excellence in 2015
  • Named to Lawdragon Magazine's "500 Leading Lawyers in America" list in 2015
  • Selected by clients and peers as being among the world's leading investigations lawyers in the 2015 edition of Who's Who Legal: Investigations and Who's Who Legal: Business Crime Defence
  • Recognized in the International Who's Who of Investigations Lawyers in 2014 and selected for inclusion in each edition of the International Who's Who of Business Crime Lawyers from 2008-2014, with sources recently saying she is a “first-class litigator”
  • Recognized as one of Massachusetts' leading lawyers in litigation, specifically in white-collar criminal litigation and government investigations, in the 2005-2013, 2015 and 2016 editions of Chambers USA: America's Leading Lawyers for Business. Ms. Green was also recommended in the field of healthcare law in the 2014 and 2015 editions.
  • Recipient of the 2015 Excellence in Complex Business Litigation - Massachusetts Award from Corporate LiveWire
  • In the 2011-2012 Best Law Firm rankings by U.S. News - Best Lawyers, a client described Ms. Green as "very bright, knowledgeable, and direct"  
  • Named a "New England Super Lawyer" (formerly "Massachusetts Super Lawyer") in white-collar criminal defense in the 2005-2015 issues of Boston Magazine. Ranked among the "Top Women Attorneys in Massachusetts" in 2016, the "Top 50 Women Massachusetts Super Lawyers" in 2004, 2006, 2012, 2013, 2014 and 2015 and as one of the "Top 100 Massachusetts Super Lawyers" in 2004 and 2005.
  • Selected as one of three lawyers profiled in SuperLawyers Magazine/New England in 2014, p.8-10 and cover
  • Recognized in Lawyer Monthly magazine's Women in Law Awards in 2014, an annual list highlighting the achievements of women in the legal professional across the globe
  • Named a "Life Sciences Star" in the 2012, 2013 and 2014 editions of LMG Life Sciences
  • Listed in the 2006 and 2013 editions of Lawdragon Magazine for work on behalf of pharmaceutical, medical device and other health care companies
  • Listed as a "leading lawyer" in the field of government enforcement & investigations law by the PLC Cross-border Life Sciences Handbook, 2009/2010
  • Fellow, Litigation Counsel of America (Member, Thomas A. Mesereau Cup Selection Committee)
  • Honoree, Granada House Annual Dinner, 2002, for pro bono legal work on behalf of group home for disabled persons
  • Recipient of the 2001 Women's Business Hall of Fame Award
  • Recipient of the Patriots' Trail Girl Scout Council, Inc.'s Leading Women 2000 Award
  • Recipient of the 1997 Park Street Forum's Award for Outstanding Service to the City of Boston
  • Profiled as one of Boston's Top Women Lawyers, The Boston Globe, 1996

Publications & News


June 16, 2016

Supreme Court Upholds Implied Certification Liability, While Emphasizing Materiality Requirement

In Universal Health Services v. United States ex rel. Escobar, the Supreme Court unanimously upheld the “implied certification” theory of liability under the False Claims Act (FCA), while emphasizing that only material misrepresentations are actionable.

May 27, 2016

WilmerHale Lawyers and Practices Recognized in 2016 Edition of Chambers USA

Chambers USA: America's Leading Lawyers for Business announced its final rankings for the 2016 edition, with WilmerHale ranking among the nation's best in 47 practice area categories. Chambers also ranked 82 WilmerHale lawyers as leaders in their respective fields.

March 18, 2016

Karen F. Green Named President of Litigation Counsel of America

LCA is an invitation-only trial lawyer honorary society established to reflect the new face of the American Bar.

January 12, 2016

False Claims Act: 2015 Year-in-Review

In 2015, the Justice Department continued to give high priority to False Claims Act investigations, bringing in nearly $3.6 billion in settlements and judgments. 

November 19, 2015

Karen Green Honored Among Mass Lawyers Weekly 2015 Top Women of Law and Inducted Into Circle of Excellence

Massachusetts Lawyers Weekly has named longtime WilmerHale Partner Karen Green to its Top Women of Law list for 2015—a recognition that honors “women who have made tremendous professional strides and demonstrated great accomplishments in the legal field.”

September 14, 2015

LMG Life Sciences Release 2015 Rankings, Again Names WilmerHale a "Life Cycle Firm"

In its latest edition, LMG Life Sciences recognizes eight WilmerHale practice areas and 16 attorneys, and for the fourth consecutive year names WilmerHale a "Life Cycle Firm."

May 19, 2015

WilmerHale Practices, Lawyers Ranked Among Nation’s Best by Chambers USA

Chambers USA: America's Leading Lawyers for Business announced its final rankings for the 2015 edition, with WilmerHale ranking among the nation's best in 46 practice area categories. Chambers also ranked 86 WilmerHale attorneys as leaders in their respective fields.

January 29, 2015

False Claims Act: 2014 Year-in-Review

The federal government collected a record-breaking $5.7 billion in False Claims Act (FCA) recoveries in fiscal year (FY) 2014, up from $3.8 billion in FY 2013.

October 21, 2014

Karen Green Featured in Cover Story of New England Super Lawyers

Partner Karen Green is featured on the cover of the 2014 New England Super Lawyers Magazine and is the subject of its story, "The Details and the Big Picture."

April 9, 2014

Testify First, Know Why Later: Responding to Civil Investigative Demands for Testimony in False Claims Act Cases

An article co-authored by Karen Green, published in the April 2014 edition of Financial Fraud Law Report.

Recent Highlights

As select examples, Ms. Green has represented:

  • an Internet search and technology company in a grand jury investigation of alleged aiding and abetting of unlawful conduct by Canadian online pharmacies;
  • a device manufacturer in connection with the resolution of claims that it had breached a deferred prosecution agreement;
  • an international development organization in an internal investigation into the conduct of one of its senior officers;
  • a public company in a grand jury investigation of alleged government program fraud;
  • a former officer of a major public company in an FCPA investigation;
  • a major pharmaceutical company in parallel criminal and civil investigations of alleged off-label promotion and improper payments in connection with the marketing of six drugs, and assisted it in globally resolving those investigations, four related qui tam actions, and related administrative claims;
  • a medical device manufacturer in a grand jury investigation by the US Attorney for the District of New Jersey and assisted it in globally resolving the government’s criminal, civil and administrative claims;
  • a major medical device manufacturer in a six-year, grand jury investigation by the United States Attorney's Office in Boston into the distribution of an allegedly adulterated and misbranded stent delivery system; the matter was resolved on a civil basis and neither the company nor two officers, who had been designated as targets, were indicted;
  • a defense contractor in a qui tam action, which was dismissed with prejudice, under the False Claims Act;
  • a third party billing company in parallel civil and criminal investigations by the US Attorney for the Southern District of New York of alleged Medicare and Medicaid fraud;
  • a supplier of durable medical equipment in a grand jury investigation by the US Attorney for the Southern District of Florida of alleged Medicare fraud;
  • multiple former employees in civil and criminal investigations by the US Attorney for the District of Massachusetts of alleged off-label marketing of a drug;
  • an office products supplier in a qui tam False Claims Act suit filed in the District of Columbia allegedly arising from the sale of office supplies to the US government that originated from impermissible countries under the Buy American Act;
  • a medical device manufacturer in an investigation by the US Attorney for the District of Massachusetts arising from the sale of allegedly defective blood analyzers to the US Army;
  • a medical device manufacturer in an investigation by the US Attorney for the District of Columbia of alleged violations of the Export Control Act;
  • a printed circuit board manufacturer in a criminal case charging violations of the federal Clean Water Act;
  • the former President and CEO of a health insurer in a federal grand jury investigation;
  • a company's former CEO and director in parallel civil, criminal and Congressional investigations of alleged improprieties in government contracting;
  • a national retailer in parallel civil and criminal proceedings alleging bankruptcy and mail fraud; and
  • various companies in corporate internal investigations.

Professional Activities

Ms. Green is President of Litigation Counsel of America, a trial lawyer honorary society, and a member of the Trial Law Institute and the Diversity Law Institute. She is also a director of CareGroup, Inc., an organization of teaching and community hospitals; a trustee of Massachusetts Eye and Ear; and a trustee of the Massachusetts Taxpayers Foundation. In 2014, she chaired the Search Committee tasked with selecting the Foundation's president.  

Ms. Green was appointed to a special commission charged with investigating allegations of inmate abuse and financial mismanagement at the Suffolk County Sheriff's Department. She also formerly served as: a director of the Harvard Club of Boston, Fiduciary Trust Company, The Fenn School, the Harvard Alumni Association, The Boston Club and the Children's Trust Fund; vice-chair of the Massachusetts Supreme Judicial Court's Committee on Pro Bono Legal Services; a member of the First Circuit Court of Appeals' Advisory Committee on the rules of practice and internal operating procedures, the First Circuit Court of Appeals' Gender Bias Committee, the US District Court's Committee to Revise the Local Criminal Rules, the US District Court's Committee on Alternative Dispute Resolution, the Boston Bar Association Council, and the Executive Committee of the Massachusetts Judicial Nominating Council; an instructor in Harvard Law School's Trial Advocacy Workshop and the United States Attorney General's Advocacy Institute; a trustee of the Boston Bar Foundation; and chair of the Boston Bar Association's Federal Practice and Procedure Committee.


Skip Navigation Links.


JD, cum laude, Harvard Law School, 1981

AB, magna cum laude, Harvard University, 1978, Phi Beta Kappa

Bar Admissions


New York

United States Supreme Court


The Hon. W. Arthur Garrity Jr., US District Court for the District of Massachusetts, 1981 - 1982

Government Experience

Skip Navigation Links.