A nonprofit organization is a legally structured entity formed to serve a public or social mission, with a defining rule that any money left over after expenses must be reinvested in the mission rather than paid out to owners, shareholders, or the people running it. Nonprofits can earn revenue, hold assets, pay staff, and grow. What they cannot do is distribute their surplus as profit. That single constraint, more than the type of work they do, is what makes them nonprofits.
The category covers a huge range of activity: hospitals, universities, churches, food banks, animal shelters, museums, trade associations, and advocacy groups. They differ in size and purpose but share the same structural commitment to public benefit over private gain, and most operate under a layered set of federal and state tax rules that follow from that commitment.
The Rule That Defines a Nonprofit
Legal scholars call it the non-distribution constraint, and it is the single most important rule governing nonprofit operations. A for-profit company can pay its surplus to owners. A nonprofit cannot. Every dollar left after expenses has to go back into the organization’s work.
The constraint reaches anyone who controls the organization, including board members, officers, and voting members. None of them can receive a share of earnings. They can be paid reasonable compensation for work they actually perform: an executive director can earn a salary, and a board member who provides consulting services can be paid a fair market rate. The line sits at compensation that exceeds what a comparable position would pay at a similar organization. Cross it, and the IRS treats the excess as “inurement,” which can jeopardize the organization’s tax-exempt status.
How a Nonprofit Is Formed
Becoming a nonprofit is a two-step process, and the steps are often confused with each other.
The first step happens at the state level. An organization files articles of incorporation with the state’s secretary of state or an equivalent agency. The articles have to identify the organization’s purpose and commit to the non-distribution constraint. Filing fees generally run from about $30 to a few hundred dollars depending on the state. Once accepted, the organization exists as a legal entity that can open bank accounts, sign contracts, and hire employees.
State incorporation, by itself, does not make an organization tax-exempt. It creates a nonprofit corporation under state law, but the entity still owes federal corporate income tax on its earnings until the IRS says otherwise. Federal tax exemption is a separate designation, obtained through a separate application.
Federal Tax-Exempt Status
Federal tax exemption is granted by the IRS and, when approved, removes federal corporate income tax on revenue connected to the organization’s exempt purpose. The exemption categories live in Section 501 of the Internal Revenue Code, and different categories carry different rules.1Office of the Law Revision Counsel. 26 USC 501 – Exemption From Tax on Corporations, Certain Trusts, Etc.
501(c)(3): Charitable, Religious, and Educational
The best-known category is Section 501(c)(3), which covers organizations operated for religious, charitable, scientific, literary, or educational purposes, along with the prevention of cruelty to children or animals. Organizations apply on IRS Form 1023, which requires a detailed description of planned activities, governance, and financial projections. The user fee is currently $600, with a streamlined Form 1023-EZ available to smaller organizations for $275.2Internal Revenue Service. Form 1023 and 1023-EZ: Amount of User Fee
The big practical advantage of 501(c)(3) status is that donations to the organization are generally tax-deductible for the donor, which makes fundraising easier. The tradeoff is a strict limit on political activity, discussed below.
501(c)(4): Social Welfare Organizations
Section 501(c)(4) covers social welfare organizations that promote the common good of a community. These groups are also exempt from federal income tax, but donations to them are generally not tax-deductible for the donor.3Internal Revenue Service. Donations to Section 501(c)(4) Organizations In return for that limitation, 501(c)(4) organizations have more freedom to lobby and engage in political activity than 501(c)(3) charities do.
Public Charity vs. Private Foundation
Inside the 501(c)(3) universe there is a second sorting. Every 501(c)(3) is automatically classified as a private foundation unless it qualifies as a public charity.4Internal Revenue Service. EO Operational Requirements: Private Foundations and Public Charities The difference is where the money comes from.
A public charity draws a substantial portion of its support from the general public, government grants, or earned revenue. The IRS measures this with a public support test over a five-year period, generally requiring at least one-third of support to come from public sources.5Internal Revenue Service. Exempt Organizations Annual Reporting Requirements – Form 990, Schedules A and B: Public Charity Support Test Churches, schools, and hospitals qualify as public charities automatically.
A private foundation is typically funded by a single family, individual, or corporation. Because private foundations are less exposed to public scrutiny, they face additional operating rules, including mandatory annual distributions and excise taxes on investment income. Public charities avoid those rules, which is why most new nonprofits aim for public charity classification.
What Tax Exemption Does Not Cover
Federal exemption is narrower than it sounds. Two areas commonly surprise people.
State taxes are separate. A federal determination letter does not automatically exempt an organization from state income tax, sales tax, or property tax. Most states require their own applications, and requirements vary. Skipping the state step can leave an organization owing state taxes even with federal exempt status in hand.
Unrelated business income is still taxable. When a nonprofit regularly runs a business activity that is not substantially related to its exempt purpose, the income from that activity is subject to unrelated business income tax. Three conditions have to line up: the activity is a trade or business, it is regularly carried on, and it is not substantially related to the mission.6Internal Revenue Service. Unrelated Business Income Defined A museum gift shop selling posters of the collection is mission-related. The same museum renting its parking lot to commuters year-round probably is not. If unrelated business gross income reaches $1,000 or more, the organization files Form 990-T and pays tax on the net income.7Internal Revenue Service. 2025 Instructions for Form 990-T
Some activities are excluded from the tax. Work done almost entirely by volunteers, sales of donated merchandise (like thrift shops), and convenience operations for members or students (like a university cafeteria) are outside the rule.8Internal Revenue Service. Unrelated Business Income Tax Exceptions and Exclusions Passive investment income like dividends, interest, and royalties is also generally excluded.
Political Activity: Two Different Rules
The political rules trip up more 501(c)(3) organizations than almost any other compliance area, largely because people confuse lobbying with campaign activity. They are not the same.
Political campaign activity is an absolute prohibition for 501(c)(3) organizations. The organization cannot endorse candidates, contribute to campaigns, or make public statements for or against anyone running for office. There is no threshold and no safe harbor. Any amount of campaign intervention can cost the organization its tax-exempt status.1Office of the Law Revision Counsel. 26 USC 501 – Exemption From Tax on Corporations, Certain Trusts, Etc.
Lobbying, meaning efforts to influence specific legislation, is different. A 501(c)(3) is allowed to lobby, but it cannot be a “substantial part” of the organization’s overall activities, measured by the IRS through a facts-and-circumstances test that weighs both time and money.9Internal Revenue Service. Measuring Lobbying: Substantial Part Test General advocacy and public education that does not reference specific legislation is unlimited. Organizations under 501(c)(4) have more room and can lobby as their primary activity.
Transparency Through Form 990
Because nonprofits benefit from a public subsidy in the form of foregone tax revenue, they are expected to operate in public view. The primary mechanism is the annual Form 990, the Return of Organization Exempt From Income Tax. The version filed depends on the organization’s size:
- Form 990-N (the electronic “e-Postcard”) for organizations with gross receipts normally $50,000 or less.
- Form 990-EZ for organizations with gross receipts under $200,000 and total assets under $500,000.
- The full Form 990 for organizations with gross receipts of $200,000 or more, or total assets of $500,000 or more.
The Form 990 is a public document. It discloses revenue, expenses, program activities, governance practices, and compensation of officers and key employees. Organizations must make their annual returns available for public inspection for three years beginning with the filing due date or the date actually filed, whichever is later.10Internal Revenue Service. Public Disclosure and Availability of Exempt Organization Returns and Applications: Public Disclosure Overview In practice, most Forms 990 are indexed online, and nonprofit finances are more openly accessible than those of most private companies.11Internal Revenue Service. 2025 Instructions for Form 990
Excess Benefit Transactions
When someone with substantial influence over the nonprofit receives compensation or other economic benefits that exceed the fair market value of what they provided, the IRS treats it as an excess benefit transaction. The person who received the excess owes a tax equal to 25 percent of the excess amount. If it is not corrected within the taxable period, a second tax of 200 percent kicks in.12Office of the Law Revision Counsel. 26 USC 4958 – Taxes on Excess Benefit Transactions Organization managers who knowingly approved the transaction face their own penalty of 10 percent of the excess benefit, capped at $20,000 per transaction.
These “intermediate sanctions” exist because revoking an organization’s exempt status often hurts the people it serves more than the people who caused the problem. Targeting the individuals responsible lets the IRS penalize misconduct without dismantling the nonprofit.
Automatic Revocation for Non-Filing
One rule catches smaller organizations more than any other. If a tax-exempt organization fails to file its required annual return (Form 990, 990-EZ, or 990-N) for three consecutive years, the IRS automatically revokes its tax-exempt status. Revocation takes effect on the filing due date of the third missed return.13Internal Revenue Service. Automatic Revocation of Exemption
There is no warning, no appeal, and no discretion. The law does not allow the IRS to undo a proper automatic revocation. Getting exempt status back means applying again and paying the user fee a second time. During the gap, the organization owes federal income tax on its earnings and cannot offer donors a tax-deductible receipt. For a small nonprofit that simply forgot to file its five-minute e-Postcard, the reinstatement bill dwarfs the effort the filing would have taken.
When a Nonprofit Closes
The non-distribution rule follows the organization even to its end. When a nonprofit dissolves, the remaining assets cannot be divided among board members or staff. The organizing documents of a 501(c)(3) must include a dissolution clause committing that assets will be distributed to another tax-exempt organization or to a government entity for a public purpose, and the IRS checks for that clause during the initial application.14Internal Revenue Service. Does the Organizing Document Contain the Dissolution Provision Required Under Section 501(c)(3)
When the organization actually winds down, it files a final return. Form 990 and 990-EZ filers check the “Terminated” box and complete Schedule N, showing how the assets were distributed. The final return is due by the 15th day of the fifth month after the termination date.15Internal Revenue Service. Termination of an Exempt Organization The state where the organization was incorporated has its own dissolution paperwork; skipping it can leave a defunct nonprofit on the state’s books, quietly accumulating penalties for missed filings years after operations stopped.