Federal 25C Energy Tax Credit: What Changed for 2026
Check the installation date before counting a federal credit alongside a Mass Save incentive.
The short answer
For a home improvement placed in service in 2026, leave the federal 25C credit out of the budget. A qualifying 2025 installation is a different question. Note when the equipment was ready for use and check the IRS instructions for that year before relying on a proposal or receipt.
Which date matters?
The federal cutoff is December 31, 2025. Paying a deposit in December for equipment first placed in service the following January does not preserve the 25C credit. If your paperwork spans the cutoff, locate the dated invoice and installation record and use the IRS guidance for the relevant tax year.
Read a 2026 proposal without double-counting savings
Start with the contractor’s installed price. Deduct only the rebates that apply to your model, household and installation date. If a quote for new work still subtracts a federal 25C credit, ask for a revised balance. A 0% loan can change when you pay that balance; it does not reduce the purchase price.
What to keep for a 2025 project
Save the paid invoice, model information, installation date and rebate paperwork. The IRS Form 5695 instructions explain the applicable equipment and manufacturer identification requirements. If an earlier installation or a rebate changes your tax calculation, bring those records to your tax preparer rather than treating an installer’s estimate as your tax result.
Common questions
Does the end of 25C end my Mass Save rebate?
No. The federal income tax credit and Mass Save rebates have different rules. Check the Massachusetts offer for the particular upgrade, equipment and installation year. A project can qualify for a program incentive even when a newly installed system no longer qualifies for the federal credit.
Which federal credit covers rooftop solar?
Rooftop solar was addressed by the separate residential clean energy credit, not the 25C home improvement credit discussed here. The federal rules and end dates are stated separately by the IRS. For a new project, request a written solar estimate that identifies each incentive and the dates on which it relies.
Related: 2026 rebates and financing · All homeowner guides
Sources and further reading
Use these guides to prepare questions; equipment and costs need to be assessed for your home.
Your next step
Bring your questions. Start with your home.
Tell us what you want to improve and what you would like to understand. Send a request; your appointment is confirmed separately.