Jennifer Kies Mammen counsels clients on a variety of national security issues including structuring transactions to protect business-critical facility clearances and secure approval from the Committee on Foreign Investment in the United States (CFIUS). She frequently advises companies and individuals regarding security clearances, including all aspects of compliance with federal regulations relating to individual clearances, facility clearances, and foreign, ownership, control, or influence (FOCI) and has successfully represented individuals in gaining and retaining individual clearances at hearings before the Defense Office of Hearings and Appeals.

In addition to national security matters, Ms. Mammen represents companies and individuals in a variety of matters related to federal regulations and government contracts, including investigating, defending, and negotiating federal criminal and regulatory matters and claims brought under the FCA and FCPA. Her investigations-related work has involved assisting clients under investigation by the Department of Justice, the Securities Exchange Commission, the Nuclear Regulatory Commission, and the Commodity Future Trading Commission. She also advises employers on preparing policies and procedures to address whistleblowers and prevent retaliation.