IRS Publication 557 is the definitive "bible" for organizations seeking to understand, apply for, and maintain tax-exempt status under Section 501(c) of the Internal Revenue Code. Updated for 2025, this comprehensive guide covers the spectrum from the initial application process to operational compliance. Key Strengths

Publication 557 is indispensable for non-profit founders, board members, and tax professionals. However, because it is technical, it is highly recommended to use this in conjunction with professional legal or tax advice, rather than in isolation.

(e.g., nonprofit board members, donors, researchers)

Detailed instructions on using Form 1023 (for charitable organizations) and Form 1024 (for other exemptions).