The Rule That Catches Foundations by Surprise
Most of the private foundation excise taxes announce themselves. You notice the 5% distribution requirement because you have to calculate it every year. You notice the tax on net investment income because you're writing quarterly checks for it.
Excess business holdings is different. A foundation can sit in violation of IRC §4943 for years without anyone at the table realizing it, because nothing changed — the foundation simply received what the founder left it. Then the 990-PF preparer asks whether the foundation holds more than a 2% interest in any business enterprise, and a board discovers it owns 60% of a company it has to sell.
If you've inherited a private foundation that holds an interest in a family business, this is the rule to check before anything else on the compliance list. It is the one with a deadline attached.
What the 20% Rule Actually Says
Under §4943(c)(2), a foundation has excess business holdings when the foundation and all of its disqualified persons together own more than 20% of the voting stock of a business enterprise.
The aggregation is the part people miss. Under §4946, disqualified persons include any substantial contributor (anyone who gave more than $5,000 where that also exceeds 2% of total contributions), every foundation manager — officers, directors, and trustees, whether or not they ever gave a dollar — and the family of both groups. "Family" is a closed list: spouse, ancestors, children, grandchildren, great-grandchildren, and the spouses of those descendants. Siblings, nieces, and nephews are not disqualified persons.
Then the category where the arithmetic usually goes wrong: an entity is itself a disqualified person when disqualified persons own more than 35% of it — 35% of a corporation's voting power, a partnership's profits interest, or a trust's beneficial interest. That is far below the 50% most people assume, so a family LLC held 40% by the founder's children aggregates. Related private foundations count too.
So the arithmetic looks like this:
| Holder | Voting stock | |---|---| | The foundation | 14% | | Founder's surviving spouse | 9% | | Two adult children | 6% | | Combined | 29% |
The family group is 9 percentage points over. The foundation only owns 14%, but the foundation is what gets taxed — the excise tax falls on the charity, not on the relatives whose personal holdings pushed the group over the line. That asymmetry is worth explaining out loud to a family board, because it means a child buying more shares of the family company can create a tax bill for the foundation.
Nonvoting stock is treated separately, and the test is narrower than you'd guess. A foundation may hold any amount of nonvoting stock so long as the disqualified persons hold no more than 20% of the voting stock — the foundation's own voting stock is excluded from that particular test. So a foundation at 18% voting with disqualified persons at 5% has a voting problem, but its nonvoting stock is entirely permitted. This is the single most useful planning fact in the section, and we'll come back to it.
A true sole proprietorship is a hard zero. Under §4943(c)(3)(B), permitted holdings in a sole proprietorship is 0% — no 20% allowance. But "sole proprietorship" is a term of art: the foundation owns 100% of the equity, directly. An unincorporated business the foundation owns only a piece of is treated as a partnership or other unincorporated enterprise, where the ordinary 20% cap applies. And a zero permitted holding doesn't mean instant tax — a business received by bequest still gets the five-year disposal period below.
What Isn't a "Business Enterprise" at All
Before calculating anything, confirm the asset is even in scope. Section §4943(d)(3) carves two categories out of the definition:
Passive holding companies. An entity deriving at least 95% of gross income from passive sources — dividends, interest, rents, royalties, annuities, capital gains — is not a business enterprise. A family LLC holding triple-net leased real estate usually clears this; a company that manages its own properties and serves tenants usually does not. A single active year doesn't necessarily blow the exclusion, since the regulations let you substitute the entity's ten-year average. And if the exclusion is genuinely lost, it drops away going forward rather than retroactively.
Functionally related businesses. A trade or business substantially related to the foundation's exempt purpose is excluded. This exception is narrower than families want it to be: the business itself must advance the mission, not merely generate money that funds the mission. A foundation-owned bookstore attached to an educational program qualifies. A foundation-owned equipment dealership whose profits fund education grants does not.
Note the distinction from unrelated business income tax, which asks whether income is taxable. Section 4943 asks a different question — whether the ownership stake is permitted — and a holding can be fine under one rule and a problem under the other.
The Exceptions Worth Knowing
The 2% de minimis rule. Under §4943(c)(2)(C), if the foundation — together with any related private foundations — owns 2% or less of the voting stock and 2% or less in value of all outstanding shares, it has no excess holdings, no matter what the family owns. Small legacy positions in a closely held company frequently land here, and a board that assumes the family aggregation rule swallows everything can spend money solving a problem it doesn't have. Treat it as a cliff, not a cushion: cross 2% on either the voting or the value prong and the safe harbor disappears entirely.
The 35% cap. When effective control of the business is genuinely held by people who are not disqualified persons, 35% replaces 20%. This is fact-dependent rather than elective, and the control has to be established to the satisfaction of the IRS — if the family group is at 35% and no unrelated shareholder or block actually controls the company, the exception isn't available. Don't build a plan on it without counsel confirming the control facts.
The §4943(g) philanthropic business exception. Added in 2018, this provision lets a foundation hold a business enterprise outside the 20% cap entirely — but only on all-or-nothing terms, and the conditions are strict:
- The foundation owns 100% of the voting stock. A foundation sitting at 60% cannot use this provision at all.
- All of that ownership was acquired other than by purchase — gift or bequest, not a buy.
- The business distributes an amount equal to its net operating income to the foundation each year, within 120 days of the close of the taxable year.
- The business is independently operated: no substantial contributor or family member serves as a director, officer, trustee, manager, employee, or contractor — the 1099 consulting arrangement counts — and a majority of the foundation's own board is independent of both the business and the contributor group.
- The business has no outstanding loans to a substantial contributor or family member.
The independence requirement is where most families stop, because the whole point of keeping the business is usually that the family keeps running it. But for a donor who wants the company itself to become the endowment and is willing to hand operations to independent management, §4943(g) is a real path, and it is thinly covered by most foundation resources. It is not available to donor-advised funds, Type III supporting organizations, or split-interest trusts.
The Clock: Five Years, Starting Later Than You Think
When a foundation receives business holdings by gift or bequest rather than purchase, §4943(c)(6) gives it a five-year disposal period. During that window, the holdings are treated as held by a disqualified person instead of by the foundation, which means no excise tax accrues while you work on an exit.
For holdings received under a will or trust, §4943(c)(6)(B) sets the start date at the date the estate or trust distributes the stock to the foundation — not the date of death. A probate that runs two years pushes the deadline out two years with it. Boards regularly get this wrong in both directions: some panic against a deadline that hasn't started, and others assume they're inside a window that closed while the estate was open.
Two additional timing rules, and the difference between them is worth four and three-quarter years:
- A disqualified person buying more shares gives you 90 days, not five years. The purchase carve-out in §4943(c)(6) applies to purchases by the foundation or by a disqualified person, so a family member increasing their personal stake starts a 90-day clock for the foundation to get back under the line. A corporate redemption of other holders is different — when the company buys out someone else and everyone's percentage rises passively, the foundation didn't purchase anything, and the full five-year disposal period applies from the date of the redemption.
- Under §4943(c)(7), a foundation that received an unusually large gift or bequest of diverse business holdings, or holdings with a complex corporate structure, can ask for one additional five-year extension. It has to file a disposition plan with the IRS, and with the state attorney general, before the first five years expire, and show diligent efforts to sell that failed at anything close to fair value. The IRS may grant it — this is discretion, not entitlement. Waiting until year five to think about the extension is how foundations lose it.
Then the Tax
The initial tax is 10% of the value of the excess holdings, measured at the largest excess held on any day during the year, for each year the excess persists at the close of the tax year. If the foundation still holds the excess at the end of the correction period — which starts at 90 days after the IRS mails a notice of deficiency and can be extended by a Tax Court petition or by the IRS itself — the second-tier tax is 200% of the value of the excess.
On a $2 million excess position: $200,000, then $4 million. The structure is deliberate. The first tier is a signal; the second tier is designed to make holding out irrational. Both are computed on Form 4720 (Schedule C) and filed alongside the Form 990-PF, where Part VI-B asks directly whether the foundation held more than a 2% direct or indirect interest in any business enterprise during the year. Answer it against an actual cap table, not from memory — that question is the point at which most foundations discover they have a problem.
Fixing It Without Creating a Second Problem
Here is the trap that turns one violation into two: the obvious fix — selling the foundation's shares to the family — is prohibited self-dealing under §4941, even at a fully appraised fair market value. Section 4941 doesn't care that the sale was required by another section of the code. (One wrinkle: the prohibition only bites if the buyer is actually a disqualified person, and as noted above, a sibling or a niece isn't one. Confirm who's on the list before assuming either way.)
Four routes that generally work:
1. A pro-rata corporate redemption. Section 4941(d)(2)(F) permits a redemption or recapitalization involving a corporation that is a disqualified person, provided all securities of that class are subject to the same terms and those terms give the foundation at least fair market value. The company makes the same offer to every holder of the class; the foundation tenders; its percentage drops. This is the workhorse solution and it needs to be papered as a general offer, not a side deal.
2. Recapitalize into nonvoting stock. Because the cap runs on voting power, converting the foundation's shares to a nonvoting class can cure the violation without anyone selling anything — the family keeps control, the foundation keeps the economics. It is harder than it sounds: the same uniform-terms requirement applies, so you can't convert only the foundation's shares — the offer has to run to the entire class, which means the other holders have to be willing. Add valuation questions on top. When the class will cooperate, though, it's the one route that solves the problem without anyone selling a business they want to keep.
3. Sell to a genuine third party. Straightforward when there's a market. Illiquid minority stakes in family companies frequently have none, which is precisely the fact pattern §4943(c)(7) extensions exist for — so document every broker conversation and failed approach from year one, because that file is the extension application.
4. Structure the exit as a program-related investment. In narrow cases the foundation can lend to a buyer, or hold the interest as a PRI, which is excluded from §4943. The charitable purpose has to be primary and real, and the documentation has to be built before the transaction, not after.
Whichever route you take, run the disposition past the jeopardizing investment rules and confirm how the proceeds land against the 5% payout — a large liquidity event changes next year's required distribution.
Check This Before It Has a Deadline
Excess business holdings is a solvable problem when it is found early and an expensive one when it is found late. Most of the cost is in lost time: the five-year window closed, the extension wasn't filed, the pro-rata redemption became a private sale because nobody knew the difference.
If your foundation holds any interest in an operating business — directly, through an LLC, or through a partnership nobody has looked at since the estate closed — the work is to establish four facts: whether the entity is a business enterprise at all, what the full disqualified-person group owns, when the disposal clock started, and what an exit that survives §4941 actually looks like.
That mapping is the first phase of the Foundation Transition Navigator, and it's a standard part of a foundation governance review. If you just need someone to look at a cap table and tell you whether you have a problem, a foundation advisory call is usually enough to answer it.
The rule doesn't punish foundations for owning a business. It punishes them for still owning too much of one after the time ran out.