Glossary · Programs & credentials
One Big Beautiful Bill Act (OBBBA)
Also called: OBBB · One Big Beautiful Bill · Public Law 119-21 · P.L. 119-21
The July 4, 2025 US tax law that ended the 25C and 25D home energy credits after 2025 and the 45L new-home credit after June 30, 2026.
What it means
Public Law 119-21 moved up the end dates for several Inflation Reduction Act tax credits. For homeowners, 25C (efficiency upgrades) ended for property placed in service after Dec 31, 2025, and 25D (clean energy equipment such as solar and geothermal heat pumps) ended for expenditures made after Dec 31, 2025, with the installation completion date, not the payment date, deciding which year counts.
Why it matters in an audit
It's why there's no federal tax credit for 2026 efficiency upgrades, so budgets should rely on rebates and utility programs instead.
Typical numbers
Reference values with their sources. Your auditor’s report gives the figure for your own house.
| What | Value | Source |
|---|---|---|
| 25C end | Not allowed for property placed in service after Dec 31, 2025 | irs.gov ↗ |
| 25D end | Not allowed for expenditures made after Dec 31, 2025; paying in 2025 for a system finished in 2026 doesn't qualify | irs.gov ↗ |
| 45L end (new homes, builder credit) | Not allowed for homes acquired after June 30, 2026 | irs.gov ↗ |