This chapter refers to the most important federal tax laws relating to nonprofit governance. It addresses the relationship between tax-exempt status and advocacy for “social justice” that is an important public policy issue. The chapter describes the type of nonprofit organization, the primary responsibilities of directors, trustees, and officers, how to address conflicts of interest and related party transactions, important governance rules related to fundraising and what legal rules affect nonprofit organizations engaging in advocacy for social justice. A nonprofit status is generally a state law concept that may make an organization eligible for benefits such as state income, sales, and property tax exemption. The ultimate legal authority and responsibility for a nonprofit organization lie with the governing board, which is composed of directors or trustees. The chapter concludes by extracting some general principles and best practices for good governance of nonprofits.