OpenAI PPUs explained: what they are, how they're taxed, and what's happening to them

Why OpenAI used PPUs instead of stock

Most startups grant equity through stock options (ISOs or NQSOs) or restricted stock units because they're Delaware C-corporations, which is the standard structure for VC-backed companies. OpenAI was different: it was organized as a for-profit LLC controlled by a nonprofit (OpenAI Inc.), a structure designed to cap investor returns and direct "excess" value to the nonprofit's mission.

LLCs don't have "stock." They have membership interests. So OpenAI compensated employees with profit participation units — a form of LLC interest that entitles the holder to a share of profits above a specified threshold (the "participation threshold"). The threshold is set so that at the time of grant, the PPU has minimal present value, mirroring the economics of an option granted at-the-money.

The result: PPU holders participate in upside just like option holders, but the instrument is structured as an LLC equity interest rather than a right to buy corporate shares. That distinction has significant tax and planning implications.

The return cap: what it was and what it meant

OpenAI's capped-profit structure placed a ceiling on returns for investors and, reportedly, on some categories of PPU holders. Publicly reported caps were structured on a multiple-of-investment basis for early investors; the specific terms for employee PPUs were governed by individual grant agreements and were not uniformly disclosed.

What matters for planning is this: if your PPU grant document contained a return cap or ceiling on proceeds, that cap shaped how much you could receive from a tender offer or, eventually, an IPO. Some employees discovered their cap was binding only at much higher valuations; others found it relevant during the $6.6 billion October 2025 tender.²

The LLC-to-PBC conversion reportedly eliminates the cap structure for PPUs converting to PBC shares — but this is based on public reporting, not grant documents. Read your individual grant agreement to understand whether a cap ever applied and what the conversion terms say about it.

The 83(b) election: the decision that splits outcomes

The most consequential planning moment for a PPU holder was the 30 days after their grant date. Under IRC § 83,³ property transferred in connection with services is taxable when it vests — unless the holder makes a Section 83(b) election, which moves the income recognition to the grant date instead.

If a Section 83(b) election was filed

The election allowed the employee to recognize the FMV of the PPU at grant as ordinary income immediately. Because profit interests are typically issued when the participation threshold equals current value — i.e., there is no built-in spread — the income recognized at grant is usually near zero. The IRS has confirmed this treatment for LLC profit interests under Rev. Proc. 93-27 and Rev. Proc. 2001-43.⁴

After a valid 83(b) election: the holding period for capital-gains treatment starts at the grant date. An employee who received PPUs in 2021 and filed an 83(b) election has had long-term capital gains treatment on all appreciation since 2022. When those units convert to PBC shares — and eventually trade — the gain from grant-date FMV to sale price is long-term capital gains: 20% federal plus 3.8% NIIT for high earners, not 37% ordinary income.

The difference between 23.8% and 37% (plus state) on several million dollars of appreciation is the central planning fact for most OpenAI PPU holders.

If no Section 83(b) election was made

Without the election, each vesting event triggers ordinary income recognition at the FMV of the units vesting on that date. For units that vested in 2023, 2024, or 2025 — when OpenAI's valuation moved from ~$29 billion to ~$157 billion to ~$300 billion — the spread recognized as ordinary income was substantial. The holding period for capital gains purposes resets on each vest date; gains above the vest-date FMV become long-term only after another year of holding.

For unvested units still outstanding, each future vesting event will be an ordinary income event unless and until the conversion structure changes the character of the instrument in a way that alters the analysis. This is a CPA conversation, not a general-rule situation.

How PPUs compare to other equity instruments

PPUs with a timely 83(b) election are structurally more tax-efficient than ISOs (no AMT risk), RSUs (no ordinary income on appreciation), or NQSOs. The catch: the election window was 30 days from grant and is permanent. It cannot be undone, and a missed election cannot be retroactively filed.

The LLC-to-PBC conversion: what's happening to PPUs

OpenAI filed a confidential S-1 with the SEC on June 8, 2026,¹ and has restructured from its nonprofit/LLC hybrid into a Public Benefit Corporation — a standard corporate form that can list on a public exchange. As part of that restructure, PPUs are reported to automatically convert into PBC shares under the following terms (based on public reporting; verify against your own conversion documents):

• One-for-one conversion. Each PPU converts to one PBC share, though the precise ratio depends on the conversion mechanics in your grant agreement.
• Basis and holding period carry over. The conversion is not a taxable sale — your existing cost basis (either ~$0 from a filed 83(b), or the vest-date FMVs for each lot) and your original holding-period start dates transfer to the new shares. The conversion does not reset your capital-gains clock.
• Return cap disappears. PBC shares have no embedded ceiling on proceeds; your upside tracks the full share price from conversion forward.
• What's uncertain: whether any aspect of your specific grant's conversion terms creates a taxable event depends on the fine print of your unit agreement, the conversion ratio, and whether any "exchange" mechanics trigger a § 1001 realization event. The IRS has not issued specific guidance on OpenAI's structure. A CPA who has reviewed the PBC conversion documents for other employees is the right resource here.

Historical liquidity: the October 2025 tender

OpenAI has run multiple investor-led tender offers. The largest reported one closed in October 2025: approximately $6.6 billion, covering 600+ current and former employees, with per-person caps reportedly raised to $30 million.² Prior tenders ran at lower valuations.

PPU holders who participated in tenders sold LLC profit interests, not corporate shares. The tax treatment of tender proceeds from a profit interest depends on basis, holding period, and the specific terms of the sale. For 83(b) filers with grant-date basis near zero and units held more than one year: proceeds are long-term capital gains in full. For non-filers: a mix of ordinary income (the basis was established at each vest-date FMV, which may already be high relative to the tender price for some vintage grants) and capital gains above basis.

What to check right now

1. Find your grant documents. Every PPU grant has an agreement. Read the participation threshold, vesting schedule, return cap (if any), transfer restrictions, and — now critically — conversion terms for the PBC restructure.
2. Confirm whether a Section 83(b) election was filed. Look for a copy of the election signed within 30 days of your grant date and a certified mail receipt. Some OpenAI employees filed; some employers filed on their behalf; many didn't know the option existed. This is the central question for your tax picture going forward.
3. Map your lots. Which PPU grants are fully vested? Which are still unvesting? What is the basis for each lot (either ~$0 if 83(b) filed, or the FMV at each vest date for non-filers)? Is each lot already long-term (held more than 1 year from the basis date)?
4. Understand the conversion terms. When does conversion happen? What's your share count post-conversion? Does any aspect of the conversion trigger income recognition? This requires the actual conversion documents, not just public reporting.
5. Model the IPO event. After conversion, your PBC shares will have a lockup period (likely staggered, as SpaceX's reported lockup schedule illustrates⁵). What is your first sellable tranche? At current valuation and your basis, what are the tax outcomes across different price scenarios?
6. Consider state residency timing. California taxes long-term capital gains as ordinary income — no preferential rate. Most OpenAI employees are California residents. If you're considering relocating before the IPO, residency and domicile requirements must be established well in advance. This is a CPA-intensive conversation, not a timing trick.

What the advisor match adds

PPUs are unusual enough that most general financial advisors have never seen one. An equity-compensation specialist who has worked through the OpenAI conversion documents, modeled PPU basis across multiple grant vintages, and structured lockup glideplans for recently-converted holders brings something a general advisor doesn't. The planning window that matters most is before you can trade — lockup periods and MNPI rules close options fast. The full OpenAI IPO guide covers next steps in detail.

PPU questions are specific. Get a specialist.

Get matched with a fee-only fiduciary who has worked OpenAI equity — 83(b) review, PPU basis analysis, PBC conversion modeling, lockup glidepath, and estimated-tax planning. Free, no obligation.