Siobhan Rausch focuses on the increasingly complex area of tax-exempt organizations. She advises charitable, educational, health and scientific research organizations; private foundations; and trade associations.

The emergence of social enterprises, proliferation of impact investing, and commercialization of research and other program activities has blurred the once sharp line between charitable and for-profit activity. Siobhan uses her technical know-how and practical judgment to help nonprofit and for-profit enterprises best navigate those lines.

Siobhan obtains IRS private letter rulings for clients and handles their complex tax-exemption applications. Organizations seek her assistance on the qualification and retention of their tax exemptions, audits, restructurings, mergers and strategic transactions, joint ventures, collaborations, investments (including program-related investments), and governance and unrelated business income tax (UBIT). Siobhan has particular experience (and has advised congressional tax-writing committee staff) on IRS supporting organization rules. She also represents a number of U.S. "friends of" organizations and international nonprofits in global microfinance and other activities. She has helped large corporate foundations structure patient assistance programs, grant programs, and disease or disaster hardship assistance programs for use in developing countries. In recent years, Siobhan has been at the forefront of investment fund structures involving charitable organizations as fund sponsors.

Siobhan is regularly recognized for her pro bono contributions and involvement with women's initiatives at Hogan Lovells.