Who We Are2021-11-22T12:06:19-05:00

International Tax Services | It’s What We Do

In 1983, we started as a typical CPA firm, doing tax, audit, and accounting. However, early on, there was a demand for tax support for international organization employees in the Washington, DC, area. These organizations, such as the World Bank and IMF, have a special status under the IRS tax code because they don’t fall under any one country’s jurisdiction. Supporting this population was our first foray into international tax. And very quickly, we shifted our focus to specializing in international and expat tax. For four decades now, we have been doing exactly that.

Today we thrive as an international tax firm—helping thousands of clients each year. And unlike most CPA firms in the United States, you won’t find us doing accounting, bookkeeping, or audit/attestation. We only work on international tax matters—it’s who we are and what every member of our team works on daily.

Our Promise to You

Providing excellent tax advice is one thing. But delivering it in a way that makes clients our biggest fans, that takes the experience to another level. What guides us? It’s the things we believe in passionately:

  • Putting our clients’ interests first
  • Taking responsibility for what needs to be done
  • Being friendly, respectful, and patient
  • Expanding our knowledge of international tax matters
  • Providing best-in-class service worthy of referrals

About Our Tax Team

We’re proud to be multi-national with backgrounds and experiences as diverse as our clients. We’re also multi-generational, from recent college grads to grandparents. And we’re multi-lingual—speaking Spanish, Chinese, French, Korean, and others. If there is a specific language in which you would prefer to communicate with us, let us know, and we will try our best to accommodate your needs.

Our Leadership Team

The Wolf Group Partners: Bob Len, Len Wolf, Jen Marenberg, and Mishkin Santa

Len Wolf, CPA, Jen Marenberg, CPA and Mishkin Santa, JD, LLM, TEP are the leadership for The Wolf Group, PC. While Bob Len, CPA, serves as the Managing Director for The Wolf Group’s sister firm, Wolf Group Capital Advisors. Combined, this team has over 90 years of experience in international tax matters.

Refer with Confidence

Need a reliable tax partner for referring? We routinely work with attorneys, wealth managers, other CPAs, and foreign tax professionals who want to refer their clients to a CPA that specializes in international tax planning.

Contact us to talk with one of our directors.

Have a tax matter outside of the US? As a member of Nexia International, we can work on tax matters around the world. Learn more.

Join The Wolf Group Team

We are always looking for highly talented professionals to join our team. Check out our available positions.

The Wolf Group’s History

Founded in 1983, The Wolf Group began its journey into international tax matters when it worked with in-house counsels at the IMF and the World Bank. This initial engagement involved tax issues for international organization employees and retirees.

In 1996, Wolf Group Capital Advisors was founded to provide wealth management services as a Registered Investment Advisory (RIA) firm, primarily for international organization employees and retirees. Today, Wolf Group Capital Advisors offers financial planning and investment services to a range of clients with cross-border needs, as well as those with only domestic interests. Learn more.

Providing Specialized International Tax Services Since 1983

November 2021


The Firm moves into new offices in Fairfax, VA, setting the stage for future growth.


Jen Marenberg becomes a shareholder of The Wolf Group, P.C. Mishkin Santa is appointed Secretary of the Society of Tax and Estate Planners (STEP) Mid-Atlantic region.

The Firm is engaged as “of counsel” equivalent to provide international/expatriate tax support to dozens of CPA and law firms in the U.S. and abroad. Mishkin Santa visits, and speaks at, NEXIA International firms across Australia.


Mishkin Santa becomes a shareholder of The Wolf Group, P.C. Mishkin Santa visits, and gives more than a dozen presentations speaks at, NEXIA International firms across Australia.


The Firm launches its blog, Cross-Border Tax Matters, to share insights on the international tax implications of popular (e.g., sports, celebrity) news stories and on new developments in the tax world.

Len Wolf authors a chapter in “The Diplomatic Handbook” published by the American Immigration Attorneys Association (AILA), entitled “Income Taxation of G-IV and A Visa Holders.”

The Firm launches its cryptocurrency tax practice.


Mishkin Santa joins the firm as International Tax Director. The Wolf Group is invited to present at the United Nations headquarters on International Organization tax matters and establishes an office presence in New York City.


The Firm is invited to present to the Florida Institute of CPAs/Florida Bar Association combined International Tax Conference in Miami, Florida, attended by 2,000 delegates from around the world.


Jen Marenberg joins the firm as a senior expatriate tax consultant. Her role in the Firm grows over the years, and she becomes an income partner 4 years later.


The Wolf Group wins the Nexia “Firm of the Year Award,” chosen from more than 200 CPA firms around the world.

The Firm also publishes a “Guide to the U.S. Taxation” for several International Organizations’ credit unions and publishes white papers on topics including “Fundamental Financial Planning and Investment Strategies for Foreign Nationals Living in the U.S.” and “Fundamental Financial Planning and Investment Strategies for U.S. Persons Living Overseas.”

The Firm sponsors a 5K Walk for Hope benefiting Access Hope, a non-profit organization dedicated to enhancing access to mental health services by underserved populations.


Len Wolf appears on the radio show, Blueprint for Wealth, and The Wolf Group chairs NEXIA International’s Global Mobility Tax Services specialty group, leading the Nexia Global Mobility Tax Forum in Paris.


The Wolf Group publishes its first internally written and published quarterly newsletter, Global Insights.


The Firm is renamed The Wolf Group, P.C.

With the merger of SCI International and NEXIA International, Len Wolf is named Co-chair of the International Tax Committee and Bob Len is appointed as a Regional Chairman (Western Hemisphere) of the combined entity.


TWG initiates a secondment program with other NEXIA International firms around the world, in which professional staff are exchanged for 6-week periods. Professional staff exchanges ensue with top quality firms in the UK, France, Germany, Singapore, Australia, and other countries.


The Firm launches its first internship program, the first of many initiatives over the decades to expose undergraduate students to international tax matters.


Our Firm joins SCI International, which later merges with Nexia International, the 9th largest accounting network in the world, according to the latest IAB World Survey. Len Wolf visits over a dozen SCI International member firms abroad.


Bob Len becomes an equity partner of the Firm.


RDL Financial, L.C. (now called Wolf Group Capital Advisors), a registered investment advisory services firm, is established to provide our clients with professional investment management and financial planning advice to supplement our tax services. Bob Len is named the Managing Director of RDL Financial, L.C.


The Firm moves to Fairfax, VA, and also establishes a satellite office in Washington, DC.

Bob Len is appointed to the role of Treasurer with British American Business Association (BABA), a role he will retain for years thereafter.


The Firm establishes a new program, Diversus, providing profitability consulting services to international businesses.


The Wolf Group could be seen at various international organizations in the U.S. and abroad speaking on the topics of tax compliance and tax planning for foreign nationals living in the U.S. and Americans abroad. The Wolf Group is now considered the premier Washington, DC-based CPA firm specializing in international and expatriate tax.


Bob Len joins as a staff accountant, becoming a minority partner of the firm 2.5 years later. His equity interest grows over the years. The Firm also moves to an office in Merrifield, VA.


Len Wolf develops a close working relationship with the in-house counsels at the IMF and the World Bank. We soon developed specialized expertise in international organization employee and retiree tax matters.

Early 1980s

The Washington, DC area’s growing telecom sector was attracting global corporations from Western Europe, Asia, and elsewhere. Several of these firms would become the first of many multinational corporations served by The Wolf Group.


Len Wolf founded the Firm in Falls Church, VA.

Why The Wolf Group?

Since 1983, we’ve worked with clients in the United States and abroad on international tax matters. We have a long history of “cleaning up” complex tax returns, reporting foreign assets, and reconstructing financial records.

Check out our extensive team of CPAs, all with vast international tax experience.

Looking for a Nexia International Partner?

We’re an active member of Nexia International, a global network of independent accountancy, tax and business advisors with over 250 firms around the globe.

Meet Our Tax Professionals

Ready for a paid consultation?

What our clients say

“The whole process was very efficiently handled with the minimum of fuss. Correspondence answered quickly and precisely. Overall, an excellent experience—we have recommended the Wolf Group to others.”

“Living overseas, your personal attention during tax time takes ALL the worry out of that one important task each year. I thank you kindly for giving me peace of mind while I live abroad.”

“Very courteous, timely, helpful service! A pleasure to do business with and we feel confident that the tax prep is done within our best interests and within the law.”

Go to Top