James Mastracchio - Winston & Strawn LLP

In the intricate and often intimidating world of federal tax law and governmental investigations, particularly when international elements are involved, businesses and individuals in the District of Columbia require legal counsel with unparalleled expertise and a proven track record. For those navigating complex civil and criminal tax controversies, or facing high-stakes white-collar investigations, **James Mastracchio**, a distinguished Partner at the globally renowned firm **Winston & Strawn LLP**, stands as one of the foremost advisers to the global tax community.

James Mastracchio brings decades of experience to his practice, including a unique background as a Certified Public Accountant (CPA) with a Big Four accounting firm prior to his legal career. This dual expertise provides him with an invaluable understanding of both the financial and legal intricacies of tax matters. He is one of the few lawyers in the country who has served as lead counsel on international criminal tax cases, defending publicly traded companies, boards of directors, and senior management against allegations of tax violations. His practice is intensely focused on resolving clients' most difficult legal and tax regulatory challenges, whether they involve civil, criminal, or parallel proceedings.

For clients in Washington, DC, dealing with federal tax disputes, IRS investigations, or sensitive governmental inquiries involving tax and financial matters, James Mastracchio offers sophisticated, strategic, and results-oriented legal counsel. He routinely represents clients before the U.S. Department of Justice (DOJ), U.S. Attorney's Offices, the Internal Revenue Service (IRS), and other regulatory agencies, demonstrating his deep familiarity with the federal landscape in the nation's capital.

James Mastracchio practices at the Washington, DC office of Winston & Strawn LLP, which is strategically located at **1901 L St NW, Washington, DC 20036, USA**. This prime address places the firm in the heart of Washington, DC's vibrant central business district, making its services highly accessible to clients throughout the District and the wider metropolitan area. The L Street corridor is a well-known hub for major law firms and professional services, chosen for its strategic location and excellent connectivity.

For those utilizing Washington, DC's efficient public transportation system, the office is within easy walking distance of several major Metro stations. These include Farragut North (Red Line) and Farragut West (Orange, Blue, and Silver Lines), providing convenient access from virtually any part of the city. Numerous Metrobus routes also operate along L Street NW and the surrounding areas, offering additional flexibility for commuters. This robust public transit access ensures that clients can reach their appointments with minimal hassle, saving time and reducing stress.

While parking in downtown DC can sometimes be a consideration, the area surrounding 1901 L Street NW offers multiple commercial parking garages, providing viable options for clients who prefer to drive. The building itself is a modern and professional environment, designed to offer a comfortable and discreet setting for confidential legal discussions. This central and well-connected location underscores Winston & Strawn LLP's commitment to providing convenient and accessible legal services to the diverse community of Washington, DC, particularly for clients engaged in highly specialized and complex tax and white-collar matters.

James Mastracchio's practice at Winston & Strawn LLP is highly specialized, focusing on civil and criminal tax enforcement matters and white-collar defense. His deep expertise in these areas allows him to provide comprehensive and sophisticated legal solutions for individuals, public and private companies, boards of directors, and senior executives. His core services include:

• Civil Federal Tax Controversies: Representing clients in all phases of federal civil tax disputes, from initial IRS Examination and Appeals to Post-Appeals Mediation and litigation in federal courts. This includes highly sensitive and high-stakes tax cases.
• Criminal Tax Investigations and Prosecutions: Serving as lead counsel in complex international and domestic criminal tax cases, defending clients facing criminal investigations and prosecutions for alleged tax violations. This is a rare specialization among U.S. lawyers.
• Parallel Proceedings: Managing cases where civil and criminal tax investigations run concurrently, ensuring a unified and strategic defense across all fronts.
• Offshore Holdings and Structured Products: Counseling clients facing investigations into offshore holdings and complex financial products, working to resolve these investigations favorably.
• False Claims Act (FCA) - Tax Division Matters: Representing clients before the U.S. Department of Justice (DOJ) Tax Division concerning tax-related False Claims Act allegations.
• IRS Offshore Voluntary Disclosure Program (OVDP): Assisting numerous taxpayers who participated in or are navigating the complexities of the IRS Offshore Voluntary Disclosure Program.
• Tax Penalty Defense: Defending taxpayers facing penalties for failing to timely file various international information reporting forms (e.g., Form 5471, Form 8938).
• State Attorneys General Tax Matters: Representing clients before State Attorneys General False Claims Divisions, particularly concerning state-level tax fraud allegations (e.g., New York State's False Claims Act).
• International Tax Authority Representation: Appearing before regulatory bodies and competent tax authorities in numerous countries, advising on international tax compliance and disputes.
• Compliance Programs: Advising on the development and enhancement of compliance programs to mitigate tax-related risks.
• Independent Examiner Roles: Served as an Independent Examiner in Zurich, Switzerland, for the DOJ's Swiss Bank Program, providing unique insight into government programs and enforcement.
• Corporate Governance & Board Advisory: Assisting boards of directors and senior executives in navigating sensitive governmental investigations involving tax and financial matters.

James Mastracchio's combination of legal and accounting expertise, coupled with his extensive experience in both the private and governmental sectors, positions him as a comprehensive and highly effective advocate for complex tax and white-collar issues.

James Mastracchio's professional profile is distinguished by numerous exceptional features and highlights that establish him as a preeminent authority in his field:

• Globally Recognized Tax Controversy Expert: He is widely recognized as one of the foremost advisers to the global tax community on civil and criminal tax enforcement matters.
• Lead Counsel in International Criminal Tax Cases: Uniquely, he is one of the few lawyers in the U.S. who has served as lead counsel on international criminal tax cases, defending publicly traded companies and senior management against serious allegations.
• Former "Big Four" CPA: His background as a Certified Public Accountant (CPA) with a Big Four accounting firm provides him with an invaluable, practical understanding of financial and accounting intricacies relevant to tax investigations.
• Independent Examiner for DOJ Swiss Bank Program: His role as an Independent Examiner for the U.S. Department of Justice's Swiss Bank Program highlights his trusted standing and deep knowledge of international tax enforcement and compliance.
• Routinely Represents Clients Before Key Agencies: He regularly appears before critical federal agencies including the U.S. Department of Justice (DOJ), U.S. Attorney's Offices, and the Internal Revenue Service (IRS), demonstrating his familiarity with the federal landscape in Washington, DC.
• Recognized by Prestigious Legal Publications: James Mastracchio has consistently received high accolades:
  • The Legal 500 US: Recognized in "Contentious Tax" (multiple years, including 2017–2020, 2022–2024) and "International Tax" (2019), and as a "Leading National Tax Controversy Attorney" (2016–2018).
  • International Tax Review Tax Controversy Leaders: Recognized as a "leading lawyer" (2016–2020).
  • Lawdragon 500 Leading Global Tax Lawyers: Featured in the inaugural edition (2025).
• Seasoned Advocate in Sensitive Governmental Investigations: He brings decades of experience representing companies, boards of directors, and senior executives in sensitive governmental investigations involving tax and financial matters.
• Focus on Early Resolution: He is a trusted adviser who consistently seeks the earliest possible resolution for civil tax disputes, whether before the IRS, Competent Authority, or in federal courts.
• Extensive Knowledge of U.S. Tax Law & Procedures: His comprehensive understanding provides invaluable representation for "bet-the-company" federal tax cases.

These highlights collectively position James Mastracchio as an elite legal professional, uniquely equipped to handle the most complex and challenging tax and white-collar defense matters for clients in Washington, DC, and globally.

Based on publicly available information for Winston & Strawn LLP and James Mastracchio, there are no specific promotions or special offers advertised in the traditional consumer sense, such as discounted legal fees or bundled service packages. This is a standard practice for large, globally recognized law firms that specialize in highly complex, high-stakes legal matters for corporate and institutional clients.

However, for companies, boards of directors, senior executives, or individuals interested in retaining the services of James Mastracchio or Winston & Strawn LLP, it is customary to arrange an initial consultation. During this consultation, which may or may not involve a fee depending on the complexity and nature of the inquiry, potential clients can discuss their specific tax controversy, criminal tax, or white-collar defense needs. This provides a valuable opportunity to understand how Mr. Mastracchio and the firm approach cases like theirs, assess the scope of work involved, and receive an overview of the fee structure. This direct engagement allows for a personalized assessment and helps establish a clear understanding of the potential legal pathways and associated costs.

While explicit "promotions" are not offered, the significant value provided by James Mastracchio stems from his unparalleled expertise, particularly his rare experience as lead counsel on international criminal tax cases and his background as a CPA. His ability to navigate intricate civil and criminal tax enforcement matters, resolve complex offshore holding investigations favorably, and advise on sensitive government inquiries ultimately offers immense value by protecting clients' financial interests, reputations, and freedom. The strategic advantage gained from his authoritative counsel often far outweighs any short-term discount.

For the most accurate and up-to-date information regarding their services, fee arrangements, or to schedule a consultation, the best course of action is to directly contact Winston & Strawn LLP through the provided contact information. Their team can provide detailed information relevant to your specific inquiry.

To connect with James Mastracchio at Winston & Strawn LLP for your complex tax controversy and white-collar defense needs in Washington, DC, you can use the following contact details:

• Address: 1901 L St NW, Washington, DC 20036, USA
• Phone: (202) 282-5849
• Mobile Phone: +1 202-282-5849

The office is conveniently located in the central L Street corridor, making it easily accessible for in-person consultations. When contacting the firm, providing a brief overview of your legal situation, especially if it pertains to federal tax disputes, criminal tax investigations, or sensitive government inquiries, will assist their team in efficiently directing your inquiry and scheduling an appropriate consultation with Mr. Mastracchio. Whether you choose to call his main office line or the mobile number, James Mastracchio and the Winston & Strawn LLP team are prepared to provide prompt and professional assistance for your high-stakes legal concerns.

For businesses, executives, and individuals within the District of Columbia facing the most complex and sensitive federal tax controversies, criminal tax investigations, or white-collar defense matters, **James Mastracchio** at **Winston & Strawn LLP** stands as an exceptionally suitable and uniquely qualified legal advocate. In Washington, DC, the epicenter of federal law enforcement and regulatory oversight, having an attorney with Mr. Mastracchio's unparalleled background and proven track record is an indispensable asset.

His distinctive experience as one of the few lawyers in the country who has served as lead counsel on international criminal tax cases, combined with his prior role as a CPA, provides him with an **unrivaled dual perspective** on both the legal and financial intricacies of high-stakes tax and financial investigations. This comprehensive understanding is crucial for DC locals, enabling him to offer sophisticated defense strategies and proactive compliance guidance that can navigate complex False Claims Act tax cases, offshore holding investigations, and internal corporate inquiries with precision and authority.

Furthermore, the firm’s prime location at **1901 L St NW, Washington, DC 20036**, ensures superb accessibility for local clients. Situated in the heart of DC’s central business district, the office is conveniently reachable via multiple Metro lines and bus routes, simplifying logistics for in-person consultations. This local presence, coupled with the extensive global resources of Winston & Strawn LLP, means that DC clients receive world-class legal representation with the convenience and personalized attention of a local expert who is intimately familiar with the federal landscape.

Choosing James Mastracchio means partnering with an attorney who combines decades of specialized experience, a profound understanding of government enforcement tactics, and a commitment to achieving the earliest possible resolution for his clients' most challenging legal and tax regulatory issues. For any Washington, DC entity or individual facing critical tax or white-collar defense challenges, James Mastracchio offers the authoritative expertise and formidable advocacy needed to navigate these complex legal landscapes with the utmost confidence.