When does the opportunity zone 180-day clock start? Every start date, explained
You have 180 days to invest a capital gain in a QOF, starting on the day the gain would be recognized for tax, usually the sale date. Partners and S corporation shareholders can instead start on the entity’s year end or its return due date. Installment-sale gains can start on each payment date or your year end, and §1256 contract gains start on the last day of your tax year.
Key takeaways
- Stock, crypto and other direct sales: day 1 is the day after the trade date; the deadline is 180 days after the sale.
- §1231 gains: each sale starts its own 180 days on its sale date, and the full gain counts (no netting first).
- K-1 gains: choose the entity’s sale date, the last day of its tax year, or the unextended due date of its return (March 15 for calendar-year partnerships).
- Gains realized in mid-to-late 2026 can often be invested in January 2027 and get OZ 2.0 rules instead of being taxed on December 31, 2026.
Start dates by type of gain
| Gain from | 180 days start |
|---|---|
| Your own sale of stock, crypto, real estate or a business | The date the gain is recognized: the sale (trade) date |
| Section 1231 property (business real estate, equipment) | The sale date of each property; the gross gain counts without waiting to net at year end |
| Partnership, S corporation, trust or estate (K-1) | Your choice: the entity’s sale date, the last day of its tax year, or the due date of its return without extensions |
| Installment sale | Each payment’s receipt date, or the last day of your tax year in which the payment is received |
| Regulated futures and other §1256 contracts | The last day of your tax year (net gain for the year) |
These rules come from the final regulations at Treas. Reg. §1.1400Z2(a)-1. The 180th day is the last day you can invest; count from the day after the start date.
K-1 gains: the most misunderstood case
When a partnership or S corporation sells something at a gain, the gain flows to you on your K-1. You can elect to start your 180 days on any of three dates: the date the entity sold, the last day of the entity’s tax year, or the due date of the entity’s return without extensions. For a calendar-year partnership that last option is March 15 of the following year, which can push your deadline to September of the next year.
The entity can also make the deferral election itself by investing the gain in a QOF at the entity level. If it does, the gain does not reach your K-1 at all.
Section 1231 gains
Earlier proposed regulations made you wait until the end of the year and invest only the net §1231 gain. The final regulations dropped that: each §1231 gain is eligible in full, and its 180 days start on its own sale date. Only gain treated as capital gain qualifies; ordinary depreciation recapture does not.
Stock and crypto
Any capital gain qualifies, not just real estate. For stock and crypto the clock starts on the sale (trade) date, and you only need to invest the amount of the gain, not the sale proceeds. Gains on assets you held as inventory, or that are taxed as ordinary income, do not qualify.
Straddling 2026 and 2027
If your window runs past January 1, 2027, the timing of the investment decides the rules. Invested in 2026, the gain is taxed on December 31, 2026 with no step-up. Invested in 2027, according to Notice 2026-40, it is deferred for five years with the 10% (or 30% rural) step-up. See Opportunity Zones 2.0.
Missed the deadline?
There is no extension. Check whether another start date applies (K-1 and installment gains have several), or use a later gain. The 180-day rule applies separately to each gain, so a new sale starts a new clock.
Frequently asked questions
When does the 180-day period start for an opportunity zone investment?
Can I invest a K-1 capital gain in an opportunity zone fund?
Do I have to wait until year end to invest a section 1231 gain?
Can I invest crypto gains in an opportunity zone?
What if the 180th day falls on a weekend?
Is it better to invest a late-2026 gain in 2027?
Sources
- Treas. Reg. §1.1400Z2(a)-1, eligible gains and the 180-day period (Cornell LII)
- 26 U.S.C. §1400Z-2 (Cornell LII)
- IRS: Invest in a Qualified Opportunity Fund
- OpportunityZone.com Q&A: when the 180-day period starts for pass-through owners
- AFS: IRS Notice 2026-40, transitional guidance on qualified opportunity zones
Reviewed Oct 10, 2026 against the Internal Revenue Code, Treasury regulations and IRS guidance. General information, not tax or legal advice; confirm your situation with a qualified adviser. Machine-readable version: Markdown.