The Spill—in 30 seconds
- The IRS says the Energy Efficient Home Improvement Credit applied to qualifying improvements through December 31, 2025.
- For windows, the old benefit was 30% of eligible product cost, capped at $600 total; installation labor did not qualify.
- State, utility and manufacturer programs may still exist, but they are not a continuation of the expired federal credit.
Window sales have always been good at turning a future possibility into today’s discount. In 2026, the easiest number to misuse is a federal tax credit that no longer applies.
The distinction matters because “tax credit,” “rebate,” “instant discount” and “estimated energy savings” are not interchangeable. One reduces federal tax liability after eligibility is established. Another may come from a utility or manufacturer. Savings are projections, not money handed back at closing.
What exactly ended?
Section 25C, commonly called the Energy Efficient Home Improvement Credit, formerly covered certain improvements to an existing primary residence. For qualifying exterior windows and skylights, the credit was 30% of eligible product cost with a combined annual cap of $600.
The IRS page now states that taxpayers could claim qualifying improvements made through December 31, 2025. It also says the property had to be placed in service during the eligible tax year. Ordering windows or paying a deposit in 2025 did not necessarily qualify if installation and readiness for use occurred later.
Even before expiration, the marketing shorthand often inflated the benefit. The $600 figure was a ceiling, not a guaranteed check. The credit was nonrefundable, eligibility standards applied, and labor to install building-envelope components such as windows did not count toward qualified expenses.
Do not let the calendar blur
A 2025 installation may be claimed on the associated federal return if all requirements were met. A window installed in 2026 is outside the period described by the IRS, even if the proposal or deposit came earlier.
Four ways a 2026 window quote can mislead without technically lying
1. “Up to $600” appears without saying the federal program expired
Old landing pages, brochures and search snippets can outlive the law. Ask the salesperson to name the program, administrator, eligibility year and official source.
2. A tax credit is subtracted like cash at installation
A federal tax credit was never the same as an installer discount. The homeowner had to qualify and claim it. In 2026, subtracting it from the “net price” is doubly misleading.
3. Labor is folded into the eligible amount
The IRS states that labor costs for installing building-envelope components did not qualify. A compliant 2025 calculation needed to isolate eligible product cost.
4. Energy savings are presented as a promise
Window performance depends on climate, orientation, frame, glazing, installation quality, air leakage and the condition of the existing windows. A generic monthly-savings number is not a site-specific guarantee.
What window incentives may still exist?
The end of Section 25C does not erase every incentive. Utilities, states, municipalities and manufacturers can run separate programs with their own dates, products and funding limits. Some programs reward whole-home efficiency rather than a single window purchase.
Verify any remaining offer with the program administrator—not only the installer. Get the model or performance specification in writing and confirm whether preapproval is required before ordering. A contractor’s confidence does not reserve funding.
Also separate incentives from financing. “No interest if paid in full” can become deferred interest if the balance survives the promotional period. The FTC advises homeowners to shop financing independently, avoid pressure, verify contractor licensing and insurance, get multiple written estimates and resist paying the full project cost up front.
How to compare replacement-window proposals in 2026
- Compare the gross installed price before any incentive or projected savings.
- Require the manufacturer, product line, frame material, glass package, U-factor, solar heat gain coefficient and installation method.
- Separate product, labor, trim, finish work, permits, disposal and repair of concealed damage.
- Ask who measures, who installs, who services warranty claims and whether labor is covered.
- Confirm lead time, deposit schedule, cancellation rights and change-order procedure.
- Get at least three estimates using comparable scope rather than comparing only the monthly payment.
Replacement may be justified by rot, water intrusion, failed seals, poor operation, comfort or a renovation—not only energy payback. A trustworthy seller should be able to explain the non-tax reasons for the project without resurrecting an expired federal subsidy.
Frequently asked questions
Is there a federal tax credit for replacement windows in 2026?
Not under the Section 25C period described by the IRS. The credit applied to qualifying improvements through December 31, 2025.
Can I claim windows bought in 2025 but installed in 2026?
The IRS ties the credit to when qualifying property is placed in service, not merely purchased. A 2026 installation falls outside the stated end date. Consult a qualified tax professional about your facts.
Was the old window credit really $600?
It was up to 30% of eligible product cost, capped at $600 total for qualifying exterior windows and skylights, subject to the annual overall limits and tax rules. It was not a guaranteed $600 refund.
Are window rebates still available?
Possibly through utilities, states, municipalities or manufacturers. Each is separate from the expired federal credit and should be verified directly before purchase.
In 2026, a good window should close tightly. So should the math in the quote.
Primary sources
- Internal Revenue Service, Energy Efficient Home Improvement Credit, accessed August 22, 2026.
- Internal Revenue Service, How to claim the credit for exterior doors, windows, skylights and insulation.
- Federal Trade Commission, How To Avoid a Home Improvement Scam, accessed August 22, 2026.