Withers LLP > Los Angeles, United States > Firm Profile

Withers LLP
1925 Century Park East
Suite 400
CA 90067
United States

Tax > Not-for-profit (nonprofit and tax exempt organizations) Tier 3

The tax-exempt practice at Withers Bergman LLP is housed within the firm’s wider private client practice group and excels in domestic and international non-profit work. Led by William Kambas in New York, the team advises cross-border gift-giving, investments and estate planning; recently promoted partner Helen Cheng in San Diego who is ‘excellent’ according to clients, is the key name for this area. Steven Chidester in San Diego represents organizations in IRS audits and handles charitable giving. Co-chair of the practice Michael Brophy  handles estate litigation, from Los Angeles. Other key contacts include Alana Petraske in New York who has a specialty advising charities to attain tax-efficient status both in the US and the UK, and Lawton Leung  in New Haven.

Practice head(s):

William Kambas; Michael Brophy

Other key lawyers:

Alana Petraske; Helen Cheng; Steven Chidester; Lawton Leung


‘The team is very responsive and knowledgeable.’

‘Helen Chang is our lead contact and an amazing attorney who seems to genuinely care about her clients.’

Work highlights

  • Advising a not-for-profit organization to help register it as a charity so that it can drive forwards its vital fundraising work in response to the pandemic.
  • Advising an innovative tech entrepreneur and philanthropist in utilizing their trust to gift billions of dollars towards education, while also saving significantly in estate taxes.

Tax > International tax Tier 4

Withers LLP advises ultra-high-net-worth individuals on international tax holdings. Splitting his time between Connecticut and New York, William Kambas focuses on US tax structuring and tax planning. In Los Angeles, Michael Brophy covers trusts and estates litigation, while Charles Kolstad is an expert in digital asset, income, and estate tax planning. Michelle Graham operates out of San Diego and advises ultra-high-net-worth individuals with US assets. 2021 saw the opening of a new Texas office, lead by cross-border tax expert Kevin Keen, who joined in March from Winstead PC. Additionally, Marsha Laine Dungog was appointed San Francisco office leader in February 2021, and specializes in Canadian and Australian tax, trust, and superannuation matters.

Practice head(s):

William Kambas; Michael Brophy


‘When it comes to cross-border international tax planning, especially related to trusts and estates, the folks at Withers Bergman are some of the best around the globe. Whether it is North America, South America, Asia, Europe, or some combination of all those locations, Withers Bergman will be able to assist.’

‘When working on international planning matters, it is important to have some of the most talented and experienced attorneys on your team. But that is not enough. You also want to work with nice people who care about their clients, which is what you will find at Withers Bergman.’

‘A very detailed knowledge of the international tax provisions of the U.S. but also of different foreign jurisdictions and specially how they interact. Withers counts with diverse professionals who were trained and practiced in foreign jurisdictions which gives them an edge on understanding how international tax structures and transactions are regulated in the different jurisdictions involved.’

‘Michelle Graham is extremely thorough in her analysis of transactions and in the advice she provides, while still being able to design and implement business-friendly and practical solutions for very complex cross-border situations. Her understanding of the Mexican legal and tax system is a huge asset that sets her apart from other U.S. practitioners whose knowledge is limited to local laws.’

‘Withers Bergman LLP is an outstanding boutique law firm specializing in all aspects of income and estate taxation, including international taxation. The firm is characterized by outstanding, brilliant attorneys who work as a team to provide outstanding client service.’

‘The team at Withers has a very good combination of strong technical skills and a strong focus on relationships. They work well together and do not hesitate to bring in colleagues that can bring additional expertise to client situations. They are very collaborative.’

‘Bill Kambas has strong technical expertise on cross-border matters and values thought leadership on both strategic legal and regulatory issues.’

Work highlights

  • Advised a successful Bitcoin investor on his contingent residency, tax and wealth planning including advice on international income and transfer tax, residency and immigration issues.
  • Advised a Zurich-based Trust Company on the purchase, financing and leasing of a new made-to-order Gulfstream G500.

The firm: Withers, known as Withers Bergman in the US, is one of the world’s first international law firms dedicated to the business, personal and philanthropic interests of successful people, their businesses, families and advisers. With over 180 partners and more than 1,000 other staff members in 17 offices across Europe, US, Asia Pacific and the Caribbean, Withers has unparalleled expertise in the key legal issues facing individuals and their families. The firm is the true definition of global, representing clients with matters across over 100 countries and has advised 25% of the Forbes 400 List of the Wealthiest Americans and 70% of The Sunday Times Top 100 Rich List.

We offer a full range of legal services from corporate, private client and tax, dispute resolution, immigration, and wealth planning in over 18 areas of focus. Our professionals collaborate seamlessly across divisions, practice groups and geographies to provide our clients with exceptional service, tailored advice and creative and practical solutions that reflect a deep understanding of the full legal landscape, market practice and our clients’ objectives. Our extensive cross-border experience coupled with the diversity of our professionals and our local law capabilities allow us to bridge business, cultural, language, legal and regulatory differences across jurisdictions.

Areas of practice
Tax: With an unrivalled team of more than 150 personal and corporate tax lawyers globally, Withers is always ready to assist in domestic and international tax planning. Our advice is knowledgeable, reliable and solution-focused. Our areas of expertise include:

  • International corporate tax
  • Income tax
  • Creating tax-efficient wealth transfer structures
  • Gift and estate tax planning
  • Tax structuring for investments or companies
  • Pre-immigration and exit-tax planning
  • Income maximization strategies
  • Domestic and international tax compliance matters
  • Tax controversy
  • Offshore planning

Corporate: Withers has been trusted advisors to successful people and businesses for more than 100 years. As a multinational, multidisciplinary law firm, we have a deep understanding of the challenges private and public companies face and we have the experience, success rate, and bandwidth to face them head on. We focus on:

  • Mergers and acquisitions
  • Fund structuring and formation
  •  Private equity funds
  • Corporate structuring and planning
  • Corporate governance
  • Financial services regulatory

Dispute resolution: Our litigation and dispute resolution group represents companies, partnerships, and individuals in developing and implementing dispute avoidance strategies, resolving disputes beneficially for our clients, and achieving outstanding results in litigation, trials and appeals. With vast experience in commercial, corporate, partnership, trusts, estates, conservatorship, art, intellectual property, employment and real estate law, we form integrated teams to handle disputes for a broad array of industries and businesses.

Legal services Wither’s lawyers advise on include:

  • Art disputes
  • White-collar defense and investigations
  • International arbitration and public international Law
  • Employment
  • Media and reputation

Private client: Withers Bergman is one of the world’s most reputable and sought-after law firms for privately held capital throughout the United States, in particular, among multigenerational, high net worth and ultra-high net worth families to service their family businesses and their global philanthropic endeavors. Today, we are the only global law firm dedicated to the personal and private capital needs of high net worth individuals and families. Our practice includes:

  • Wealth structuring
  • Cross-border planning
  • Estate planning, wills and succession
  • Trusts and foundations
  • Probate and estate administration
Marketing & Business Development Manager | New York Lauren Lundgrenlauren.lundgren@withersworldwide.com+1 212 848 9810
Marketing & Business Development Manager | California Davia Meltzerdavia.meltzer@withersworldwide.com+1 619 358 1717
Marketing & Business Development Manager | Connecticut Deena Fazziodeena.fazzio@withersworldwide.com+1 203 974 0302