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Margaret M. Cassidy

Attorney Profile

Top Rated Business & Corporate Attorney in Washington, DC

Cassidy Law
1100 H St NW, Suite 1220
Washington, DC 20005
Phone: 202-266-9928
Selected to Super Lawyers: 2019 - 2022
Licensed in Washington DC Since: 2012
Practice Areas: Business/Corporate, Government Contracts, Criminal Defense: White Collar
Attorney Profile

The founder of Cassidy Law PLLC, Margaret M. Cassidy provides a variety of legal consulting services to businesses. From the firm’s office in Washington, D.C., she represents clients throughout the greater metropolitan area. Admitted to practice in the District of Columbia since 2012, Ms. Cassidy is admitted to practice before all Ohio and Pennsylvania state courts as well. She is a 1993 Juris Doctor recipient from the University of Pittsburgh School of Law. Prior to law school, Ms. Cassidy attended Miami University in Oxford, Ohio, and she majored in finance and earned a Bachelor of Science in 1989.

Ms. Cassidy provides advice and counsel to her company clients on a variety of matters. Her experience has encompassed anti-corruption and compliance, including the federal Foreign Corrupt Practices Act of 1977 and similar laws, the defense against governmental investigations, counseling and risk avoidance, and anti-corruption audits and assessments. Ms. Cassidy has also worked with clients who are doing business with governmental agencies and bodies throughout the United States and across the world, and she has handled matters involving trade sanctions and export regulations, internal investigations, the preparation and review of cross-border contracts and relationships, anti-human trafficking laws, trade or export violation risk mitigation, and ethical supply chain mandates.

Ms. Cassidy has also worked on cases involving the False Claims Act, also known as the "Lincoln Law", and her background includes national security matters as well. After she graduated from law school, she served as an assistant district attorney in Allegheny County, Pennsylvania, and she then spent several years as the senior deputy attorney general in the Pennsylvania Attorney General's Office. Ms. Cassidy was subsequently in private industry before forming her own practice in 2012.

Practice Areas
  • 20%Business/Corporate
  • 60%Government Contracts
  • 20%Criminal Defense: White Collar
Focus Areas

Business Formation and Planning, White Collar Crime


4 Years Super Lawyers
  • Super Lawyers: 2019 - 2022

About Margaret M. Cassidy

First Admitted: 1993, Washington DC

Professional Webpage:

Representative Clients

  • Represent federal government contractors in seeking and doing business with the federal government; federal government contractors or their executives under federal government audit or investigation; office of inspector general investigations; represent federal government contractors in disputes with the federal government or in disputes with other contractors.
  • Represent defense and intelligence community contractors on matters related to NISPOM, FOCI, classified work, defense work, SBIR.


  • The intersection of law, business, criminal activity, crime, and ethics: why do some companies violate the law? what happens when they do? what is ethical? how do we get corporations to follow the law? can lawyers help and, if so, what is the lawyer’s role?, When the Writ Hits the Fan

Scholarly Lectures/Writings

  • Seminars, False Claims Act
  • Seminars, Government Procurement & Ethically Interacting with Governments
  • Seminars, Today’s General Counsel on conducting investigations
  • Seminars, FCPA and anti-corruption
  • Seminars for businesses, business executives and employees, American Bar Association
  • Seminars, Association of Corporate Counsel National Capital Region Chapter, D.C. Procurement Technology Assistance Center
  • Seminars for businesses, business executives and employees, Pennsylvania Bar Institute
  • Seminars for businesses, business executives and employees, DC Small Business Administration
  • Adjunct Faculty, George Washington School of Law

Bar/Professional Activity

  • Association of Corporate Counsel National Capital Region Chapter, Former Global Issues Forum Co-Chair
  • Chair ABA Business Law Section Corporate Compliance Committee, 2017
  • Greater Cleveland Partnership Council on Small Enterprise, Member
  • D.C. Bar’s Law Practice Management Steering Committee, Member
  • Washington D.C. Bar, presentation - Advising Clients on Developing and Executing a Corporate Compliance Program (Dec. 2016, Dec. 2017) Cleveland Metropolitan Bar Assoc. presentation -Managing Third Party & Supply Chain Risks When Working Internationally(Dec. 2017) American Bar Assoc., presentations - Managing Third Party & Supply Chain Risks When Working Internationally(Nov. 2017); Minimizing Third Party Risks with Compliance and Ethics Contract Clauses(Sept. 2016); Conflicts of Interest(Sept. 2017); Anti-Money Laundering Regulatory and Enforcement Trends and Their Impact – Not Just a Banking Issue(Nov. 2016) C. Procurement Technology Assistance Center Annual Forum, presentation - Working with Governments(May 2017, June 2016) Pennsylvania Bar Institute, presentation - Managing Third Party Risk (June 2016; Nov. 2016); Legal Requirements for a Corporate Compliance and Ethics Program (annually since 2009) Today’s General Counsel, Ethics and Compliance Forum Leader (April 2016 to present); Cybersecurity & Privacy Forum Leader (Nov. 2015 to present) George Mason University Procurement Technology Assistance Center, presentation - Defense Federal Acquisition Regulations Compliance including export, international security, know your business partner, corruption and other DFAR compliance requirements (Nov. 2017)
  • Moderator for Todays General Counsel Ethics & Compliance Forums, 2015
  • Appointed Vice-Chair Programming for the ABA Business Law Section International Coordinating Committee, 2018
  • ABA Business Law Today Article, June 2016 - Practical Steps to Mitigate Corruption Risks in Hiring  Cleveland Metropolitan Bar Magazine Article, Nov. 2016, Using Compliance and Ethics Contract Clauses to Manage Third Party Risk
  • Elected Member of DC Bar Law Practice Management Community, 2015

Educational Background

  • Miami University, Oxford OH, BS Finance, 1989

Other Outstanding Achievements

  • Selected by the ABA as one of 11 members who inspired in 2019. ABA 11 Members Who Inspired in 2019, 2019

Pro bono/Community Service

  • Court Appointed to DC Board of Professional Responsibility, 2019


  • , Appointed to ABA Business Law Section Publications Board , American Bar Association, 2020
  • Immediate Past Chair the ABA Business Law Sections Corporate Compliance Committee for 2017-2018., Chair - American Bar Association Business Law Section Corporate Compliance Committee, American Bar Association, 2017

Industry Groups

  • All
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Office Location for Margaret M. Cassidy

1100 H St NW
Suite 1220
Washington, DC 20005

Phone: 202-266-9928

Last Updated: 5/15/2022

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