Phillips & Cohen whistleblower attorneys honored as 2021 ‘500 Leading Lawyers in America’

NEW YORK CITY, Jan. 20, 2021 – Lawdragon magazine has named six Phillips & Cohen partners to its 2021 “500 Leading Lawyers in America” list for their outstanding work representing whistleblowers.

Phillips & Cohen partners Mary Louise Cohen, Erika Kelton, Peter Chatfield, Colette Matzzie, Stephen Hasegawa and Sean McKessy are included in the 2021 edition of Lawdragon’s elite list.

  • Mary Louise Cohen is one of the firm’s founding partners. For her pioneering whistleblower cases and her important contributions to the qui tam bar, Lawdragon named Cohen “a legend for creating [the] qui tam/whistleblower practice.”
  • Erika Kelton is internationally recognized for her record-shattering work representing whistleblowers. She represented the leading whistleblowers in two of the largest healthcare fraud settlements ever: $3 billion by GlaxoSmithKline and $2.3 billion by Pfizer. In addition, she won one of the largest awards under the SEC whistleblower program – more than $32 million – for an international whistleblower client.
  • Peter Chatfield has represented whistleblower clients for over two decades, notably notching successes in complex healthcare fraud cases. Among Chatfield’s most significant wins are representing the key whistleblowers in a $881  settlement by HCA, a for-profit hospital chain, and a $425 million settlement by drugmaker Cephalon (now part of Teva Pharmaceutical Industries).
  • Colette Matzzie has represented whistleblowers in a number of important cases, including the landmark eClinicalWorks case that marked the first major fraud case against an electronic health records vendor and settled for $155 million.
  • Stephen Hasegawa had several recent successes representing whistleblowers in qui tam cases alleging healthcare fraud and customs fraud. He spearheaded a qui tam case that was part of a multi-party, $39.5 million settlement against medical equipment maker ResMed last year. He also represented a whistleblower in a qui tam case against multinational company Linde GmbH that alleged the company and its subsidiary evaded customs duties and settled for $22.8 million.
  • Sean McKessy is the former Chief of the Securities and Exchange Commission’s Office of the Whistleblower and now represents whistleblowers in securities fraud cases. He is considered one of the top authorities on corporate compliance and securities whistleblower law.

This is the 14th year in a row that Lawdragon has recognized Phillips & Cohen partners in its annual list of the “500 Leading Lawyers in America” for their work representing whistleblowers.

Lawdragon also included all of the newly honored Phillips & Cohen attorneys in the 2020 edition of its “500 Leading Plaintiff Financial Lawyers” list. This list highlights lawyers who specialize in representing litigation plaintiffs in securities matters, as well as in antitrust and corporate whistleblower cases.

Lawdragon utilizes a combination of editorial research, law firm submissions and online nominations to select attorneys to its rankings.

If you are aware of fraud against the government or corporate wrongdoing that violates securities or commodities laws and would like to discuss your situation with experienced whistleblower lawyers, contact Phillips & Cohen for a free, confidential review.


Phillips & Cohen is the most successful law firm representing whistleblowers, with recoveries from our cases totaling over $12.8 billion. We have been recognized for our work by numerous national awards. Our attorneys and cases have been in The New York TimesThe Wall Street Journal, the Financial Times and other news media. Phillips & Cohen’s roster includes former federal prosecutors, the first head of the SEC Office of the Whistleblower, a former deputy administrator of the Centers for Medicare and Medicaid Services, the author of a leading treatise on the False Claims Act and attorneys with decades of experience representing whistleblowers.



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