What Happens to Your Opportunity Zone Deferred Gain on December 31, 2026?

If you deferred a capital gain into a Qualified Opportunity Fund (QOF) any time since 2018, the deferral ends on December 31, 2026. The gain you set aside is included in your 2026 income, you pay the tax with your 2026 return, and the IRS has now confirmed that you cannot roll it into the new version of the program. What you keep is the part most investors care about most: the potential to exclude appreciation on the fund interest itself after a 10-year hold.

Several of my Houston clients hold QOF interests from business or real estate sales in 2019 through 2022, so this question has come up a lot since the IRS issued its transition guidance. When CNBC asked me about it in July, my answer was the same one I give clients: hopefully you planned for it, realize you'll owe tax on these gains, and set aside the money to pay it.

This is general education, not advice for your specific situation.

Why does the deferral end on December 31, 2026?

The original Opportunity Zone law, written in 2017, always had a fixed end date. Gain invested in a QOF was deferred only until "the earlier of" an inclusion event or December 31, 2026 (IRS Opportunity Zone FAQ, Q30).

This is not a small group. Treasury's Office of Tax Analysis counted about 12,800 Qualified Opportunity Funds with roughly 41,000 investors at the end of 2024, holding $75 billion of deferred gains; about 85% of the investors are individuals, with a typical adjusted gross income of $738,000 (CNBC).

The 2025 tax law (the One Big Beautiful Bill Act) made the program permanent going forward, but it did not extend the old deadline. In Notice 2026-40, the IRS spells out that a taxpayer holding a qualifying investment through December 31, 2026 must include the remaining deferred gain in the tax year that includes that date, which the notice calls "deemed included gain." The same notice says that amount "may not be deferred pursuant to either prior or current" law, because the original deferral election is still in effect for that gain.

How much gain will show up on my 2026 return?

Not necessarily the whole amount. Per the IRS FAQ, the amount included depends on the fair market value of your qualifying investment on the inclusion date and any adjustments to your basis in it (IRS FAQ, Q30). In practice:

• If the fund is worth more than the deferred gain, you include the deferred gain, less any basis step-ups you earned.
• If the fund is worth less than the deferred gain, the inclusion is limited to the fund's value on December 31, 2026, so a decline in the fund reduces the taxable amount.
• Basis step-ups depend on when you got in. Investors who were in a QOF by the end of 2019 get a 15% basis step-up, so 85% of the deferred gain is taxed; those in by the end of 2021 get 10%. Anyone who invested in 2022 or later could not reach the five-year mark by the end of 2026 and includes essentially the full deferred gain (CNBC).

The gain keeps its original character and is taxed at 2026 rates. For most of my clients that means the 20% long-term capital gains rate plus the 3.8% net investment income tax, which applies above $250,000 of modified AGI for joint filers (IRS). Your QOF should send you the information needed to update Form 8997, which reports the QOF investments and deferred gains you hold at the beginning and end of each tax year.

Where does the cash to pay the tax come from?

This is the practical problem. The gain is taxed, but the money is still inside the fund, and most QOFs are illiquid real estate or operating-business vehicles with no redemption before year 10.

Options I review with clients, in rough order of preference:

1. Cash already set aside. When we plan a sale, the tax on a deferred gain gets its own line in the cash-flow plan. This is the year that reserve gets used.
2. Fund distributions. Some QOFs have distributed cash from refinancing or operations to help investors cover the tax. Confirm whether those distributions reduced your basis, because that changes the included amount.
3. Other portfolio assets. Selling appreciated stock to pay the tax triggers more gain, so look first at cash, bonds, or positions with high basis or losses that can be harvested against the inclusion.
4. Timing of estimated payments. The inclusion lands in the fourth quarter of 2026, so the final 2026 estimated payment, due January 15, 2027, is the natural place for it. If your 2025 AGI was over $150,000, paying in 110% of your 2025 tax through withholding and estimates protects you from an underpayment penalty regardless of the 2026 amount (IRS).

Related reading: our year-end tax planning checklist covers the estimated-payment safe harbor and the other December 31 deadlines that interact with a large gain year.

Do I lose the 10-year benefit?

No. Paying the tax on the deferred gain in 2026 ends the deferral, not the investment. If you hold the qualifying investment for at least 10 years and make the election when you sell, your basis is adjusted to the fund interest's fair market value, so appreciation on the fund itself is never taxed (IRS FAQ, Q5 and Q25).

Notice 2026-40 confirms two helpful details. First, a taxpayer who recognizes deemed included gain in 2026 "remains potentially eligible" to make the 10-year election on a later sale. Second, for sales before January 1, 2048, the election is not impaired solely because the zone's designation has expired. The original zone designations end December 31, 2028 (December 31, 2027 for Puerto Rico), so this matters for anyone with a 2019 to 2021 investment whose 10th anniversary falls after the tract loses its status (IRS Notice 2026-40).

One real example: in a case study on our site, a client who sold a stake in a manufacturing company invested $100,000 of gain into a QOF holding a solar project. His deferred gain will be included in 2026; his 10-year clock on the fund itself keeps running.

What is different about Opportunity Zone investments after 2026?

The new rules apply to amounts invested in a QOF on or after January 1, 2027. The IRS notice lays out the mechanics:

Sources: IRS Notice 2026-40, HUD Opportunity Zones updates, Rev. Proc. in IRB 2026-20.

If your fund is still deploying capital, two transition points matter. Property acquired after 2026 for use in an original 2018 zone generally does not qualify unless it falls under a written working-capital plan adopted by December 31, 2026 (with at least 10% of the planned capital received and 5% spent by that date) or is an ordinary-course replacement of existing business property. Treasury also released proposed regulations on the new information-reporting rules this month (Baker McKenzie).

I have a capital gain from 2026. Should I invest it in a QOF now or wait?

For clients who sold a business, property or concentrated stock this year, timing matters more than usual:

• Investing in the rest of 2026 gives you no deferral. The gain would be included on December 31, 2026 regardless, so the only benefit of a 2026 investment is the 10-year exclusion on future fund appreciation.
• Investing on or after January 1, 2027 gets the new rules. The IRS notice confirms that eligible gain realized "on, before, or after December 31, 2026" may be deferred by a timely investment made on or after January 1, 2027. That means a five-year deferral, a 10% basis step-up at year five, and the 10-year exclusion.
• Your 180-day window decides whether you have the choice. The window starts on the date the gain would otherwise be recognized (IRS FAQ, Q22). A gain realized on July 6, 2026 or later has a window that reaches into 2027. Partners and S corporation shareholders may be able to start their window at the entity's year-end or its return due date instead, which can push the deadline out further (IRS FAQ, Q23).
• The fund universe will be different. New investments must generally go into tracts designated in 2026, so 2027 funds will be new offerings.

Whether a QOF belongs in your plan at all is a separate question. It's an illiquid, concentrated 10-year investment, and the tax benefit only matters if the project performs. We cover the alternatives, from installment sales to charitable strategies, in how to reduce capital gains taxes when selling a business.

Your 2026 Opportunity Zone checklist

• Pull your most recent Form 8997 and confirm the deferred gain amount and the date of each QOF investment
• Ask the fund for its estimated fair market value as of December 31, 2026 and whether any distributions reduced your basis
• Project the 2026 inclusion: gain character, federal rate and net investment income tax
• Identify the cash source for the tax and decide whether it goes into the January 15, 2027 estimate or is covered by the 110% safe harbor
• Harvest losses before year-end if they can offset part of the inclusion
• Calendar the 10-year anniversary of each QOF investment and keep the election in mind for any sale before 2048
• If you have a 2026 gain not yet invested, map the 180-day window and compare a 2026 investment with a 2027 one
• Confirm your fund's plan for post-2026 property acquisitions if it is still deploying capital

How we help

The 2026 inclusion is a known tax bill with a known date. The planning questions are the cash source, the interaction with other 2026 income, and whether the fund still fits your plan for the rest of the hold.

At Mercer Street we work on an hourly, fee-only basis and don't sell investments or manage assets. Limited-scope planning, with no comprehensive plan required, is billed at $600 per hour with a two-hour minimum; clients who have completed a comprehensive plan pay our best rate of $450 per hour. See our services page for how an engagement works.

If you hold a Qualified Opportunity Fund interest and want to model the 2026 inclusion before year-end, schedule a call.