What Is a Private Foundation? Rules, Taxes, and Deductions

A private foundation is a tax-exempt charitable organization under Internal Revenue Code Section 501(c)(3) that is funded by a single individual, family, or company rather than by broad public fundraising. Because the money comes from one concentrated source, Congress placed private foundations under a stricter regime than public charities: a mandatory annual payout of at least 5% of net investment assets, a yearly excise tax on investment income, and a set of penalty taxes for prohibited transactions that can reach 200% of the amount involved.

How a Private Foundation Differs From a Public Charity

Every 501(c)(3) organization is treated as a private foundation by default. Section 509 of the Internal Revenue Code works by exclusion: it lists the categories that qualify as public charities, and anything that doesn’t fit is a private foundation.¹

The dividing line is funding. To be a public charity, an organization generally must receive at least one-third of its support from the general public, government grants, or a combination of the two over a five-year measurement period. An alternative test under Section 509(a)(2) looks at whether the organization receives more than one-third of its support from public contributions and program revenue while receiving no more than one-third from investment income.² A foundation funded by one donor or one family fails these tests. That concentrated funding is the reason for the heavier regulation.

The 5% Annual Distribution Rule

A non-operating private foundation must distribute a minimum amount for charitable purposes every year. The rule prevents founders from parking assets in a foundation indefinitely while claiming tax benefits. The minimum payout equals 5% of the fair market value of the foundation’s net investment assets, reduced by certain taxes already paid.³

Qualifying distributions include grants to public charities, program-related investments, and the reasonable administrative expenses directly tied to charitable activities, such as staff salaries and overhead for the grantmaking program. A foundation can also count amounts “set aside” for a specific project as a qualifying distribution in the year of the set-aside, provided the money is actually spent on that project within 60 months.⁴

Missing the deadline is expensive. An initial excise tax of 30% applies to any income that remains undistributed past the deadline. If the shortfall is not corrected by the end of the taxable period, a second-tier tax of 100% applies to whatever amount is still undistributed.³

Excise Tax on Investment Income

Every tax-exempt private foundation pays an annual excise tax of 1.39% on its net investment income. The base covers interest, dividends, rents, royalties, and capital gains, minus allowable deductions. The rate was reduced from 2% in 2020 and remains at 1.39% for 2026.⁵ This isn’t a penalty. It’s a routine cost of operating a foundation, meant to offset the government’s regulatory and audit expenses for the sector.

Self-Dealing and Other Prohibited Activities

The self-dealing rules under Section 4941 are the strictest restrictions a foundation faces, and they trip up more foundations than any other rule. The law imposes a near-total ban on financial transactions between the foundation and its “disqualified persons.” A disqualified person includes any substantial contributor, foundation manager, anyone who owns more than 20% of a business that is a substantial contributor, and family members of all those individuals. Family, for this purpose, means a spouse, ancestors, children, grandchildren, great-grandchildren, and the spouses of those descendants.⁶ Corporations, partnerships, and trusts in which those people collectively hold more than 35% ownership are also disqualified persons.

Prohibited transactions include selling or leasing property between the foundation and a disqualified person, lending money in either direction, providing goods or services, and paying compensation beyond what is reasonable and necessary. It doesn’t matter whether the transaction was at fair market value or even beneficial to the foundation. If it happened, it’s self-dealing.⁷

The initial excise tax is 10% of the amount involved per year, paid by the disqualified person. A foundation manager who knowingly participated owes 5% per year. If the self-dealing isn’t corrected within the taxable period, the penalties jump to 200% on the disqualified person and 50% on any manager who refused to agree to the correction.⁷

Three other categories of prohibited activity carry their own excise taxes:

Taxable expenditures. A 20% tax applies to spending on political campaigns, lobbying, grants to individuals without advance IRS approval of the selection process, grants to organizations other than public charities without exercising “expenditure responsibility,” and grants for non-charitable purposes.⁸ A manager who knowingly approved the expenditure owes an additional 5%, capped at $10,000 per expenditure.

Excess business holdings. A foundation and its disqualified persons together generally cannot own more than 20% of the voting stock of any business enterprise. If a third party effectively controls the business, the limit rises to 35%. Holdings above the limit trigger an initial tax of 10% of the excess value, and 200% if the foundation doesn’t divest by the end of the correction period.⁹

Jeopardy investments. Speculative or excessively risky investments that jeopardize the foundation’s ability to carry out its charitable purpose trigger a 10% initial tax on the foundation and 10% on any manager who willfully approved them. The additional tax after failure to correct is 25% on the foundation and 5% on the manager.¹⁰

What Donors Can Deduct

Contributions to a private foundation are deductible, but the ceiling is lower than for gifts to a public charity. Cash contributions are limited to 30% of the donor’s adjusted gross income. Donations of long-term appreciated property, such as publicly traded stock held for more than a year, are capped at 20% of AGI.¹¹ Cash gifts to a public charity are deductible up to 60% of AGI, and appreciated stock up to 30%.¹²

There is a further wrinkle for non-publicly-traded property. When you donate property other than publicly traded stock to a private foundation, the deduction is generally based on your cost basis rather than fair market value. Real estate you bought for $200,000 that is now worth $500,000 produces a $200,000 deduction if donated to a private foundation. The same property donated to a public charity produces a $500,000 deduction. Amounts exceeding the AGI limits in any year carry forward for up to five additional tax years.

Operating Foundations Are Treated Differently

Not every private foundation is a passive grantmaker. A private operating foundation actively runs its own charitable programs, such as a museum, research lab, or housing facility, rather than simply writing checks to other charities. To qualify, the foundation must spend at least 85% of its adjusted net income (or its minimum investment return, whichever is less) directly on active charitable work, and it must meet one of three additional tests related to assets devoted to exempt activities, the level of qualifying distributions, or the breadth of its public support.¹³

Two rules relax when a foundation qualifies as operating. Donors who give cash to a private operating foundation can deduct up to 50% of AGI rather than the 30% limit that applies to other private foundations.¹⁴ Operating foundations are also exempt from the 5% minimum distribution requirement, since their direct charitable spending already puts the assets to work.³

Private Foundation or Donor-Advised Fund?

For donors weighing how to structure their giving, a donor-advised fund is the most common alternative. A DAF is an account held at a sponsoring charity, such as a community foundation or a financial institution’s charitable arm, where the donor contributes assets, takes an immediate deduction, and then recommends grants over time. The vehicles differ on the points that usually decide the choice.

Deduction limits are higher for a DAF: 60% of AGI for cash and 30% for appreciated stock, versus 30% and 20% for a foundation.
A DAF has essentially no setup cost and no ongoing filing requirements for the donor. A private foundation requires state incorporation, a federal application, annual Form 990-PF filings, and ongoing legal and accounting costs.
A foundation gives the donor or family board direct control over investment and grantmaking decisions. A DAF donor only recommends grants; the sponsoring organization has final authority.
Foundations must distribute at least 5% of net assets annually. DAFs have no mandatory payout timeline under current federal law.
DAF donors can give anonymously. Foundations file publicly available returns disclosing grants, board members, compensation, and investment fees.
Foundations pay the 1.39% annual tax on investment income. DAFs do not.

For donors focused on tax efficiency and simplicity, a DAF is usually the better fit. A foundation makes sense when the donor wants hands-on control, plans to involve future generations in governance, or intends to run programs directly rather than just make grants.

Setting One Up and Keeping It Running

Forming a private foundation involves both state and federal steps. There is no federal minimum dollar amount required, though the IRS considers a foundation’s distribution clock to start once its distributable amount exceeds $500.¹⁵ State incorporation fees for a nonprofit entity range from roughly $8 to over $1,000.

You start by creating a legal entity at the state level, usually a non-stock corporation or a charitable trust. The organizing documents must limit the organization’s purposes to those recognized under Section 501(c)(3) and include a dissolution clause directing remaining assets to another exempt purpose if the foundation ever shuts down.¹⁶ After the entity exists, you apply for an Employer Identification Number using Form SS-4¹⁷ and file Form 1023 electronically through Pay.gov to request recognition of tax-exempt status.¹⁸ The user fee is $600 for the full Form 1023; a streamlined Form 1023-EZ costs $275 and is available to some private foundations meeting size and activity thresholds, though private operating foundations cannot use it.¹⁹

Once approved, every private foundation must file Form 990-PF each year, regardless of income level. The form reports financial activity, calculates the excise tax on investment income, and tracks whether the foundation met its minimum distribution requirement.²⁰ The return is due on the 15th day of the fifth month after the close of the foundation’s tax year, which is May 15 for calendar-year filers. An automatic six-month extension is available by filing Form 8868.²¹

Form 990-PF is a public document. Grants, investments, officer compensation, and administrative expenses are all visible. Many states also require separate annual charitable registration filings with the attorney general’s office, with fees that vary by state.

Closing or Converting

A foundation that no longer wants to operate has two paths: terminate and pay a tax, or convert into a public charity.

Voluntary termination under Section 507 triggers a tax equal to the lower of the foundation’s net asset value or the aggregate tax benefit that the foundation and its donors received from its tax-exempt status over its lifetime. That aggregate benefit includes every income tax deduction donors claimed, plus every dollar of income tax the foundation avoided, plus interest on those amounts running back to when each benefit arose.²² For a long-running foundation with substantial assets, the tax can be enormous. A foundation can avoid it entirely by distributing all its assets to one or more public charities before terminating.

The other route is converting to a public charity. The foundation notifies the IRS and then must meet the public support tests under Section 509(a) for a continuous 60-month period. If it succeeds in broadening its donor base enough to pass the one-third public support threshold, the private foundation restrictions fall away and no termination tax is owed. If it fails, the foundation reverts to private foundation status for any year during the 60-month period in which it didn’t meet the tests.²²

1
Office of the Law Revision Counsel. 26 USC 509 – Private Foundation Defined
2
Internal Revenue Service. Exempt Organizations Annual Reporting Requirements – Form 990, Schedules A and B: Public Charity Support Test
3
Office of the Law Revision Counsel. 26 USC 4942 – Taxes on Failure to Distribute Income
4
eCFR. 26 CFR 53.4942(a)-3 – Qualifying Distributions Defined
5
Office of the Law Revision Counsel. 26 USC 4940 – Excise Tax Based on Investment Income
6
Office of the Law Revision Counsel. 26 USC 4946 – Definitions and Special Rules
7
Office of the Law Revision Counsel. 26 USC 4941 – Taxes on Self-Dealing
8
Office of the Law Revision Counsel. 26 USC 4945 – Taxes on Taxable Expenditures
9
Office of the Law Revision Counsel. 26 USC 4943 – Taxes on Excess Business Holdings
10
Office of the Law Revision Counsel. 26 USC 4944 – Taxes on Investments Which Jeopardize Charitable Purpose
11
Internal Revenue Service. Publication 526 (2025), Charitable Contributions
12
Internal Revenue Service. Charitable Contribution Deductions
13
Internal Revenue Service. Definition of Private Operating Foundation
14
Internal Revenue Service. Private Operating Foundations
15
Internal Revenue Service. Start-Up Period Minimum Amount: Private Foundation Set-Aside
16
Internal Revenue Service. Charity – Required Provisions for Organizing Documents
17
Internal Revenue Service. Obtaining an Employer Identification Number for an Exempt Organization
18
Internal Revenue Service. About Form 1023, Application for Recognition of Exemption Under Section 501(c)(3) of the Internal Revenue Code
19
Internal Revenue Service. Form 1023 and 1023-EZ: Amount of User Fee
20
Internal Revenue Service. About Form 990-PF, Return of Private Foundation or Section 4947(a)(1) Trust Treated as a Private Foundation
21
Internal Revenue Service. Instructions for Form 990-PF (2025)
22
Office of the Law Revision Counsel. 26 USC 507 – Termination of Private Foundation Status