Opportunity Zone 180-day deadline calculator
To defer a gain, you generally have to invest it in a Qualified Opportunity Fund within 180 days (IRC §1400Z-2(a)(1)(A)). When that clock starts depends on the kind of gain. With OZ 2.0 starting January 1, 2027, the date you invest also decides which rules apply.
Calculator
| 180-day period starts | Day 1 | Day 180 (last day to invest) | Which rules apply |
|---|---|---|---|
| Day of sale (the day the gain would be recognized) | Fri, August 14, 2026 | Tue, February 9, 2027 | Invest by Dec 31, 2026 → OZ 1.0; invest Jan 1, 2027 or later → OZ 2.0 (5-year deferral, 10%/30% step-up). |
Day 1 is the start date; we count it as the first of the 180 days, so day 180 is 179 days later. If the last day falls on a weekend or holiday, don't assume it rolls forward; invest early. Not tax advice.
When the 180 days start
- Your own sale or exchange: the day the gain would be recognized without the election, usually the sale date (Treas. Reg. §1.1400Z2(a)-1(b)(7)(i)). This also applies to qualified §1231 gains: gain above the §1245/§1250 ordinary-income recapture (§1.1400Z2(a)-1(b)(11)(iii)).
- Partnership, S corporation, trust or estate gains: by default, the last day of the entity's tax year. You can elect instead to use the entity's own 180-day period (from its sale date) or a period starting on the entity's return due date, without extensions (§1.1400Z2(a)-1(c)(8)(iii)).
- Installment sales: the date each payment is received (each payment starts a new period) or the last day of the tax year the gain is recognized (§1.1400Z2(a)-1(b)(11)(viii)(B)).
- RIC/REIT capital gain dividends: by default, the last day of your tax year; you can elect the dividend payment date instead (§1.1400Z2(a)-1(b)(7)(ii)).
The December 31, 2026 cutover
Investments made on or before December 31, 2026 follow the original rules: deferred gain is included on December 31, 2026 (IRC §1400Z-2(b)(1)). Investments made after that date follow OZ 2.0: up to 5 years of deferral, a 10% basis step-up (30% for rural funds) and the 10-year exclusion, in zones designated from January 1, 2027 (IRS Notice 2026-55; P.L. 119-21, §70421). If your 180-day window runs past December 31, 2026, the calculator shows that you could invest on either side of the cutover. Waiting for OZ 2.0 also means waiting for the new zone designations; see the OZ 2.0 tracker.
FAQ
When does the Opportunity Zone 180-day period start?
Generally on the day the gain would be recognized, usually the sale date (Treas. Reg. §1.1400Z2(a)-1(b)(7)). Pass-through gains default to the last day of the entity's tax year, with elections for the entity's sale date or its return due date.
Can I invest a 2026 gain in an OZ 2.0 fund?
If your 180-day period runs past December 31, 2026, an investment made on or after January 1, 2027 falls under the OZ 2.0 rules (IRS Notice 2026-55). Investments made on or before December 31, 2026 follow OZ 1.0, with inclusion on December 31, 2026.
Does the 180-day period apply to §1231 gains?
Yes. Under the final regulations, qualified §1231 gain (above ordinary-income recapture) uses the general rule: the period starts on the day the gain is recognized (Treas. Reg. §1.1400Z2(a)-1(b)(7) and (b)(11)(iii)).
Do installment payments each get their own 180 days?
You may treat each payment's receipt date as the start of a new 180-day period, or use the last day of the tax year (Treas. Reg. §1.1400Z2(a)-1(b)(11)(viii)(B)).
Not tax advice. This page is general information drawn from IRS forms, instructions, the Internal Revenue Code and Treasury regulations as of October 12, 2026. Rules can change and your facts matter; confirm with a qualified tax professional before you file or invest. Related: Form 8996 helper · Form 8997 helper · 180-day deadline calculator · OZ 2.0 tax calculator