OZ Fund Structuring: Qualifying Investments, the 90% Test, and QOZB Requirements

What Is a Qualified Opportunity Fund

A Qualified Opportunity Fund is a corporation or partnership organized to invest in Qualified Opportunity Zone property. The concept was created by IRC Section 1400Z-2, enacted as part of the Tax Cuts and Jobs Act of 2017, and permanently extended by the One Big Beautiful Bill Act (OBBBA) signed July 4, 2025. A QOF is the exclusive vehicle through which investors access OZ tax benefits — deferral, basis step-up, and the 10-year exclusion of appreciation from taxable income.

Unlike LIHTC partnerships or New Markets Tax Credit allocatees, a QOF does not require government approval or a competitive allocation. It is self-certified by the fund manager on IRS Form 8996 (Annual Qualified Opportunity Fund Return), filed annually with the fund's tax return. This self-certification model is intentionally low-friction, but it shifts compliance risk entirely to the fund. If the fund fails the 90% asset test in any testing period, the IRS imposes a penalty — and there is no cure provision.

For institutional CRE, the QOF is typically a limited partnership or multi-member LLC that holds one or more Qualified Opportunity Zone Business (QOZB) entities underneath it. The fund-level entity is where investors place capital. The QOZB-level entities hold the real estate. Getting this two-tier architecture right determines whether the fund's investments actually qualify — and whether investor capital gains receive the statutory benefits.

Entity Selection and Self-Certification

A QOF must be organized as either a corporation or a partnership (including a multi-member LLC taxed as a partnership). S corporations do not qualify. Most institutional QOFs are structured as limited partnerships or LLCs for three reasons:

• Pass-through taxation. Partnership income, losses, and deductions flow through to investors. No entity-level tax. This is essential because OZ investors are typically high-net-worth individuals or taxable entities that need the capital gains deferral at the individual level.
• Allocation flexibility. Partnership agreements allow custom allocation of income, gain, loss, and cash flow among partners — enabling GP/LP structures, preferred returns, and promote waterfalls that mirror standard CRE fund economics.
• Admission and redemption mechanics. Partners can be admitted at different times (each with their own 180-day investment window and holding period) without disrupting the fund's compliance status.

Self-certification happens by filing IRS Form 8996 with the fund's annual tax return. The form requires the fund to report its total assets, the value of qualifying OZ property, and whether it met the 90% test for each semi-annual testing period. Starting with tax years beginning after December 31, 2026 (the OBBBA provision), Form 8996 also requires enhanced reporting: asset types, residential unit counts, employee counts, and census tract detail for each investment.

There is no pre-approval, no allocation award letter, no state agency review. The fund simply declares itself a QOF on its first tax return and maintains compliance going forward. If it later fails, penalties apply retroactively to the testing period in which the failure occurred.

The 90% Asset Test

The defining compliance requirement for a QOF is the 90% asset test: at least 90% of the fund's total assets must be Qualified Opportunity Zone Property on each semi-annual testing date. The two testing dates are the last day of the sixth month and the last day of the taxable year. For a calendar-year fund, that means June 30 and December 31.

The 90% threshold is calculated as the average of the two semi-annual measurements. If the fund holds 85% qualifying assets on June 30 and 95% on December 31, the average is 90% — it passes. If the average falls below 90%, the fund faces a penalty.

Penalty calculation

The penalty for failing the 90% test is calculated monthly. For each month in which the fund falls below 90%, the penalty equals:

Shortfall Amount × Federal Underpayment Rate × (1/12)

The shortfall amount is the dollar amount by which the fund's qualifying assets fall below 90% of total assets. With the current federal underpayment rate at approximately 8% (Q2 2026), a fund with $50M in total assets and only $40M in qualifying property (80% instead of 90%) would face a monthly penalty of approximately $33,333 — or $400,000 annualized — on the $5M shortfall.

What counts as Qualified Opportunity Zone Property

Three categories of assets satisfy the 90% test:

1. Qualified Opportunity Zone Stock. Stock in a domestic corporation that is a QOZB, acquired by the QOF after December 31, 2017, at original issuance solely in exchange for cash.
2. Qualified Opportunity Zone Partnership Interest. A capital or profits interest in a domestic partnership that is a QOZB, acquired after December 31, 2017, solely in exchange for cash.
3. Qualified Opportunity Zone Business Property (QOZBP). Tangible property used in a trade or business of the QOF, acquired by purchase after December 31, 2017, where substantially all of the use of the property is in a qualified opportunity zone during substantially all of the QOF's holding period.

Most institutional CRE funds use options 1 or 2 — holding QOZB interests rather than holding real estate directly. This is the two-tier structure, and it provides critical operational and compliance advantages.

The Two-Tier QOF / QOZB Structure

In a single-tier structure, the QOF holds real property directly and must satisfy both the 90% asset test at the fund level and all the QOZBP requirements (original use, substantial improvement, location) for each property. In a two-tier structure, the QOF holds equity interests in one or more QOZBs, and the QOZB entities hold the real estate.

The two-tier architecture is nearly universal for institutional funds because it solves several structural problems:

• Compartmentalization. Each property sits in its own QOZB LLC. If one property fails a compliance test (say, it's partially located outside the zone boundary), that failure is isolated to one QOZB — it doesn't contaminate the entire fund.
• Capital deployment timing. The fund can acquire QOZB interests as properties are identified, without having to deploy 90% of capital on day one. As long as the QOZB interests collectively meet the 90% test on the semi-annual testing dates, the fund is compliant.
• Disposition flexibility. Individual properties can be sold by selling the QOZB interest or having the QOZB sell the property, without unwinding the fund structure. This matters for 10-year hold planning.
• Mixed investor timelines. Different investors enter the QOF at different times (each within their 180-day window). The two-tier structure allows the fund to accept new capital and deploy it into new or existing QOZBs without disrupting existing investors' holding periods.

QOZB requirements

A QOZB must satisfy four tests, each measured for substantially all of the QOF's holding period:

Table 1 — The four QOZB qualification tests. The 70% tangible property test is the binding constraint for most CRE deals. The sin business exclusion eliminates specific asset types entirely.

The critical distinction: the QOF has a 90% test (fund-level), and the QOZB has a 70% test (entity-level). The QOF's 90% test looks at the value of its QOZB interests. The QOZB's 70% test looks at the tangible property inside the QOZB. Both must pass simultaneously.

The Substantial Improvement Test

For existing buildings (as opposed to ground-up development on vacant land), a QOF or QOZB must substantially improve the property within 30 months of acquisition. Under the Treasury Department's final regulations (Treasury Decision 9889, issued December 2019), the standard rule requires the entity to invest in improvements equal to or exceeding the property's adjusted basis at the time of purchase — effectively doubling the investment in the building.

Crucially, the substantial improvement test applies to the building only, not the land. If a fund acquires a property for $8M — $3M allocated to land and $5M to the building — the improvement requirement is $5M in building improvements within 30 months. The land basis is excluded from the calculation.

How the test works in practice

The 30-month clock starts on the date the QOF or QOZB acquires the property. Improvement costs are measured by additions to basis — capital expenditures that are added to the depreciable basis of the property, not operating expenses or maintenance. Soft costs (architecture, engineering, permitting) count toward the improvement threshold if they are capitalized into the building's basis rather than expensed.

For ground-up construction on vacant land, the substantial improvement test does not apply. The property has no existing structure, so the "original use" of the building begins with the QOF. Original-use property automatically qualifies as QOZBP without needing to meet the doubling threshold.

Working Capital Safe Harbor

The working capital safe harbor allows a QOZB to hold cash and cash equivalents (which would otherwise be nonqualified financial property) without violating the 5% financial property limit, provided three conditions are met:

1. Written plan. The QOZB must have a written plan that identifies the working capital as being held for the acquisition, construction, or substantial improvement of tangible property in the OZ.
2. Written schedule. The plan must include a schedule showing that the working capital will be spent within 31 months.
3. Compliance with schedule. The QOZB must substantially comply with the written schedule.

The 31-month window is widely recognized as tight for complex CRE developments, a concern echoed by Novogradac's OZ Working Group in their comments to Treasury. A ground-up multifamily project with 18 months of entitlement, 16 months of construction, and a 6-month lease-up period easily exceeds 31 months from capital deployment to stabilization. The final regulations confirmed that the safe harbor can be used once per designated expenditure — meaning the QOZB cannot simply restart the 31-month clock.

Practitioners have developed several workarounds: phased capital calls that deploy cash only when the 31-month clock can be met, bridge financing that holds cash outside the QOZB until needed, and sequential safe harbor applications for distinct construction phases. None of these are explicitly blessed by the regulations, and the industry continues to seek a technical correction to extend the window.

OBBBA 2025: OZ 2.0 Changes

The One Big Beautiful Bill Act, signed July 4, 2025, permanently extended the Opportunity Zone program and introduced several changes that directly affect fund structuring:

Permanent extension

The program was set to expire at the end of 2028 (when current zone designations lapse). The OBBBA made the program permanent. New zone designations will be made through a process managed by the Treasury Department in coordination with the CDFI Fund, with the first redesignation cycle due July-September 2026. The Economic Innovation Group (EIG), which originally developed the OZ policy framework, has published analysis projecting that the redesignation will affect approximately 30% of current zones. Existing investments in current zones are grandfathered through 2047.

Qualified Rural Opportunity Funds (QROFs)

The OBBBA created a new fund category for investments in rural census tracts. QROFs receive two enhanced benefits:

• 30% basis step-up. QROF investors receive a 30% basis step-up at the 5-year mark (vs. 10% for standard QOFs under OZ 2.0). This is the most generous step-up in the program's history — exceeding even the original OZ 1.0 combined 15% step-up at 5 and 7 years.
• 50% substantial improvement threshold. Rural properties need only 50% of adjusted building basis in improvements (vs. 100% for standard OZ investments). Combined with lower rural construction costs, this makes acquisition-rehab deals significantly more viable in rural zones.

Enhanced reporting requirements

Starting with tax years beginning after December 31, 2026, QOFs must report additional data on Form 8996:

• Type and value of each asset held
• Number of residential units (total and affordable)
• Number of employees at each QOZB
• Census tract for each investment
• Whether the fund has elected QROF status

These reporting requirements signal the Treasury Department's intent to measure community impact more rigorously. Fund managers should build reporting infrastructure now — not in December 2027 when the first enhanced filings are due.

Elimination of 7-year basis step-up

For investments made after December 31, 2026, the OBBBA eliminated the additional 5% basis step-up that investors received at the 7-year holding mark. Only the 10% step-up at 5 years remains (or 30% for QROFs). This reduces the total deferral benefit for OZ 2.0 investors compared to those who invested under OZ 1.0.

Common Mistakes

These errors show up repeatedly in QOF formation and compliance — some are fatal, others are merely expensive:

• Deploying capital before the fund is organized. A QOF must be an entity organized for the purpose of investing in QOZ property. If you acquire property first and then form the QOF, the property was not "acquired by purchase" by the QOF. The timing sequence is: form the entity, file Form 8996 with the first tax return, then deploy capital.
• Confusing the 90% test with a one-time test. The 90% test is semi-annual and ongoing. A fund that passes on December 31, 2026 can fail on June 30, 2027 if it sold a property and hasn't redeployed the proceeds. Compliance is perpetual, not point-in-time.
• Ignoring the 31-month working capital constraint. Institutional CRE developments routinely exceed 31 months from capital call to stabilization. Holding $20M in cash inside a QOZB without a qualifying safe harbor plan turns that cash into nonqualified financial property, potentially failing the 5% test and disqualifying the QOZB.
• Failing the substantial improvement test by excluding soft costs. Architecture, engineering, and permitting fees count toward the improvement threshold if capitalized. Many sponsors track only hard construction costs against the doubling requirement and discover at the 30-month mark that they're short. Build the soft cost inclusion into your improvement tracking from day one.
• Using a single-tier structure for multi-asset funds. If one property in a single-tier fund fails a compliance test, the entire fund may fail the 90% test. The two-tier structure costs slightly more to organize but provides critical isolation.
• Missing the land exclusion in the substantial improvement test. The improvement must equal 100% (or 50% for QROFs) of the building's adjusted basis, not the total purchase price including land. Getting this wrong means the sponsor may over-improve or under-report compliance.
• Not planning for the 2026 transition. Existing OZ 1.0 investors face a mandatory gain recognition event on December 31, 2026, as specified in IRC Section 1400Z-2(b)(1). Funds should be advising investors now — not in Q4 2026 — on the tax impact, potential reinvestment into OZ 2.0 QOFs, and valuation strategies.

How to Model It

A properly built OZ fund model needs compliance tracking alongside the financial pro forma. Here's what the workbook should contain:

Fund-Level Compliance Tab

Semi-annual asset test calculation: total fund assets on each testing date, broken into qualifying (QOZB interests, QOZBP) and non-qualifying (cash, receivables, other). The 90% test result, and if failing, the shortfall amount and penalty calculation. This tab should have a row for every June 30 and December 31 over the fund's projected life.

QOZB-Level Compliance Tab (one per property)

The 70% tangible property test: unadjusted cost basis of all tangible property, with OZ-located QOZBP broken out. The 50% gross income test. The 5% nonqualified financial property test. Working capital safe harbor tracking: amount designated, written plan date, 31-month expiration date, and actual spend schedule against the plan.

Substantial Improvement Tracker

Purchase price allocation (land vs. building), adjusted building basis at acquisition, cumulative improvement expenditures by month (hard costs and capitalized soft costs), 30-month deadline, and compliance percentage (current spend / required threshold). This tab should flag when the fund is within 6 months of the deadline and below 75% of the improvement target.

Investor-Level Waterfall

Each investor's entry date, 180-day window, deferred gain amount, holding period start date, 5-year step-up date, 10-year FMV exclusion date, and projected after-tax returns under multiple exit scenarios. For OZ 1.0 investors, include the December 31, 2026 recognition event and the tax liability calculation.

Related Articles

This article is part of the Opportunity Zones underwriting series. Each article covers a distinct aspect of OZ deal structuring and investor economics:

• OZ Fund Structuring — Qualifying investment requirements, the 90% asset test, and QOZB compliance (this article).
• Investor Returns and Tax Deferral — Capital gains deferral mechanics, the December 2026 recognition event, and after-tax IRR analysis.
• Exit Timing and Disposition — The 10-year hold requirement, FMV election mechanics, and disposition planning.
• Development vs Acquisition — Original use vs. substantial improvement, vacant land rules, and choosing the right project type.