This page documents how the UnionMetric Opportunity Zone site screen produces each result, which sources it uses, how current they are, and where its limits lie. Each readout repeats the sources and load dates that applied to it.
Principles
- Primary sources for status. Designation status comes only from IRS, Treasury, CDFI Fund or state publications. Figures we could find only in secondary sources are labeled provisional.
- Point-level answers where they matter. The 2018 and 2027 maps use different census-tract vintages, so the screen tests the exact location wherever an address is available.
- Rules, not scores. The structure check applies cited rules. It does not grade feasibility, estimate value or predict returns.
- Dated everything. Each dataset carries its vintage and the date we loaded it.
Data sources
| Layer | Source | Geography | Vintage / currency |
|---|---|---|---|
| 2018 Opportunity Zones | CDFI Fund designated-tract list and boundary file | 2010 census tracts | Designations of 2018 (list updated Dec 14, 2018) |
| Rural 2018 zones | IRS Notice 2025-50 | 2010 census tracts | Sept 30, 2025 (3,309 tracts) |
| 2027 eligible tracts | Rev. Proc. 2026-14 appendix | 2020 census tracts | Apr 6, 2026; eligibility from 2020–2024 ACS 5-year data |
| 2027 entirely rural flag | Rev. Proc. 2026-14 appendix | 2020 census tracts | Apr 6, 2026 (8,334 tracts) |
| 2027 nominations | State publications only | 2020 census tracts | As published; checked weekly until certification |
| 2027 designations | IRS designation notice | 2020 census tracts | Expected before Jan 1, 2027 |
| Alternate Framework additions | Secondary source (OpportunityZones.com) | 2020 census tracts | Provisional until Treasury publishes |
| New Markets Tax Credit low-income communities | CDFI Fund 2016–2020 ACS file | 2020 census tracts | Updated Sept 9, 2026 |
| HUD Qualified Census Tracts, 2027 | HUD USER; FR 2026-20390 | 2020 census tracts | Effective 2027 |
| HUD Difficult Development Areas, 2027 | HUD USER | ZIP Code Tabulation Areas (metro); counties (non-metro) | Effective 2027 |
| State tax conformity | State revenue departments and legislation; trackers labeled as leads | State | Re-verified monthly through Q1 2027 |
| Address matching | U.S. Census Geocoder (2020 census geography) | Point to 2020 tract | Live |
How status is determined
At an address. The address is matched to a point and its 2020 census tract by the Census Geocoder. The point is tested against the 2018 zone boundaries in their native 2010-tract geometry. The 2020 tract supplies the 2027 status and the overlays. This is the authoritative mode.
At a tract (map click). Without an exact point, 2018 status is estimated from the share of the 2020 tract's land area that lies inside 2018 zones, using the Census 2020-to-2010 tract relationship file. A tract counts as "in a 2018 zone" when at least half its land area overlaps. Where the overlap is partial, the readout says so and asks for an address.
Connecticut. Data released from 2022 onward uses Connecticut's nine planning regions in place of its eight historical counties. All Connecticut identifiers are normalized to the 2020 geography before matching.
Transition classes
The 2018 status and the 2027 status combine into one of nine classes:
- Retained (zone in both maps), or retained pending certification.
- 2018 zone with an undecided 2027 status.
- Losing (2018 zone not on the 2027 eligible list) or lost (2018 zone not designated).
- New (new 2027 zone), or new pending certification.
- Eligible only.
- Not a zone.
Classes that depend on the designated list change automatically when the IRS list is loaded. The consequences shown for each class follow Notice 2026-40 and Rev. Proc. 2026-14. They are date-aware: the wording changes after December 31, 2026 and after each map's end date.
The structure check
Flags are generated by explicit rules, each tied to a statute, regulation, IRS notice or SBA rule. The citation is shown with the flag. Severity follows a simple convention:
- a blocker means the structure as described generally fails;
- a caution means an issue that must be diligenced;
- a note means context.
Rules sourced only from secondary summaries are marked as such.
Update schedule
| Trigger | Action |
|---|---|
| Weekly until Dec 28, 2026 | Re-check state nomination publications and Treasury and IRS pages |
| IRS designated list published | Load the list; tracts not on it become "not designated"; classes and pages update |
| Annual HUD QCT/DDA release | Reload overlays |
| New ACS-based NMTC file | Reload overlays |
| State conformity legislation | Update state profile and state pages |
Limitations
- The screen depends on address matching. Rural routes, new construction and incomplete addresses may not match. The map click works without an address, at tract level.
- Metro Difficult Development Areas are matched by ZIP code. That is an approximation of the ZIP Code Tabulation Area, and the readout labels it.
- HUBZone and USDA rural eligibility are not computed. The readout links to the official SBA and USDA maps.
- Status is not certification. Nominated tracts are contingent until Treasury certifies them.
- No opinion. The screen is not tax, legal, credit or investment advice and is not a feasibility study.
Corrections
If a result appears wrong, send the address, the readout date and the source you are relying on to our research team through the contact page. We review every report against the primary source and correct the data and the readout where needed.
Attribution
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau. Designation data are U.S. Government works published by the IRS, Treasury, the CDFI Fund and HUD.
How we verify this page
- Author
- Robert Mitchell
- Updated
- October 26, 2026