The short answer: for windows installed in 2026, there is no federal tax credit, and only Massachusetts has a window rebate. The IRS says the Energy Efficient Home Improvement Credit is not allowed for property placed in service after December 31, 2025.
In Massachusetts, Mass Save pays $75 per window in 2026, but only when ENERGY STAR Most Efficient windows replace verified single-pane windows. In New Hampshire, we found no window rebate from NHSaves. Everything below comes from official program pages we read on October 5, 2026. Programs change, so confirm your own eligibility before you buy.
What Is Available For Windows In 2026
| Program | Who It Covers | What It Offers For Windows | The Catch |
|---|---|---|---|
| Federal tax credit (IRC 25C) | Homeowners in both states | Nothing for 2026 installs | Ended for property placed in service after December 31, 2025 |
| Mass Save window rebate | Customers of Mass Save sponsor utilities in Massachusetts | $75 per window | Single-pane windows only, verified before install, replaced with ENERGY STAR Most Efficient windows |
| Mass Save Home Energy Assessment | The same Massachusetts customers | No window money | 75–100% off approved insulation and no-cost air sealing instead |
| NHSaves Home Energy Performance | Customers of NHSaves utilities in New Hampshire | No window rebate found | Up to $6,000 in rebates toward air sealing, insulation and other approved upgrades |
The table reflects the official pages listed under Sources, as read on October 5, 2026. None of these programs is ours, and we cannot promise any rebate or credit.
The Federal Tax Credit Ended For Windows Installed After 2025
From 2023 through 2025, the Energy Efficient Home Improvement Credit (section 25C of the tax code) helped pay for efficient windows and doors. The IRS limited the window credit to $600 total, for windows meeting ENERGY STAR Most Efficient requirements. Exterior doors were limited to $250 per door and $500 total.
ENERGY STAR describes the window credit as 30% of product cost, up to $600. It applied to products purchased and installed between January 1, 2023, and December 31, 2025.
Then the end date moved up. Public Law 119-21, signed July 4, 2025, is commonly called the One, Big, Beautiful Bill. An IRS fact sheet on that law, FS-2025-05 from August 21, 2025, is clear. The credit will not be allowed for any property placed in service after December 31, 2025.
In plain terms, a window installed in 2026 earns no federal credit, however efficient it is. If you see a window advertised as “tax credit eligible” this year, ask which credit they mean. If your windows went in during 2025, talk to your tax preparer. We install windows; we are not tax advisors.
Massachusetts: The Mass Save Window Rebate
Mass Save is the energy efficiency program offered by Massachusetts utilities and energy providers. Its 2026 window offer is real, but narrow. Here is what the published offer requires:
- $75 per window, only for ENERGY STAR Most Efficient windows replacing single-pane windows.
- The new windows must be rated Most Efficient for the Northern Region.
- Your existing windows must be verified through a Home Energy Assessment before the new windows go in.
- You must complete the weatherization recommendations made during the assessment.
- The number of windows cannot exceed the eligible windows recorded during the assessment.
- Purchases must fall between January 1, 2026, and December 31, 2026.
- You must be a residential electric or gas customer of Berkshire Gas, Cape Light Compact, Eversource, Liberty, National Grid or Unitil.
The order matters most. Once new windows are in, the old ones can no longer be verified. Book the assessment first, then order. The rebate is filed on the form provided during your assessment.
If your current windows are already double-pane, this rebate does not apply as written. Cape Light Compact’s page also notes that income-eligible customers may be able to get single-pane windows replaced at no cost. Ask your utility about that when you call.
What Mass Save Pays For Instead: Insulation And Air Sealing
For most Massachusetts homeowners, the bigger Mass Save offer is not about windows at all. National Grid’s Mass Save page describes a no-cost Home Energy Assessment, 75–100% off approved insulation and no-cost air sealing. You can schedule by calling 1-866-527-SAVE (7283).
Our honest advice for Essex County homeowners: book the assessment before you shop for windows. It costs nothing, and the window rebate requires it anyway. You will also learn which of your windows count as eligible before you sign anything. For Massachusetts pricing, see our Massachusetts window cost guide and our Harvey windows page for Massachusetts.
New Hampshire: What NHSaves Offers
As of October 5, 2026, we found no window replacement rebate on NHSaves.com. NHSaves is the energy efficiency program of New Hampshire’s electric and natural gas utilities. Its weatherization page lists air sealing, insulation, and efficient heating, cooling and water heating equipment. It does not mention windows. The 2024–2026 NHSaves plan we read mentions windows only for window air conditioners.
What NHSaves does offer can still help a drafty house:
- An online Home Heating Index tool that shows whether your home qualifies for an energy audit.
- Up to $6,000 in rebates on overall improvement costs through Home Energy Performance.
- Energy efficiency loans at 0% APR for Eversource customers. Liberty, New Hampshire Electric Co-Op and Unitil customers get 2% APR. Terms run 2 to 7 years.
Windows are not mentioned on that page, so do not count on those loans for a window project. For New Hampshire pricing, our New Hampshire window cost guide lists every model we install.
How To Check Before You Buy
Programs change, and every one of them has fine print. Before you sign for new windows, run through this list:
- Read your electric and gas bills. The utility names decide which program, if any, applies to you.
- In Massachusetts, book the Home Energy Assessment before ordering, and make sure your single-pane windows are recorded.
- Find the CPD number on the window’s NFRC label. Look it up in the NFRC Certified Product Directory for your climate zone, as ENERGY STAR describes.
- In Massachusetts, check the exact window against the Mass Save qualified product list.
- Get the exact model and glass package in writing in your quote, so you can check it.
- Keep every receipt and form until any rebate is paid.
On our side, the Gentek Series 9000 is triple pane with a .22 U-value and is ENERGY STAR Most Efficient. The Harvey Homerun is the most efficient window we sell, at a .18 U-value. Our guide to double pane vs triple pane windows explains when the extra pane earns its keep.
If no program pays toward your project, choose on comfort and budget instead. The Harvey Classic, our best seller, starts at $617 installed with a .24 U-value. Financing through Synchrony runs 0% for 18 months, with payments as low as $87/month* for a house full of windows. Our window financing guide explains how it works. *Rates and terms dependent on qualifying credit.
Frequently Asked Questions
Can I still get a federal tax credit for new windows in 2026?
No. The IRS says the Energy Efficient Home Improvement Credit will not be allowed for any property placed in service after December 31, 2025. Windows installed in 2026 do not qualify, however efficient they are.
Does Mass Save give a rebate for replacing double-pane windows?
Not under the 2026 window offer as published. The $75 per window rebate is only for ENERGY STAR Most Efficient windows that replace single-pane windows verified during a Home Energy Assessment.
Does NHSaves offer a rebate on replacement windows?
We found none on NHSaves.com as of October 5, 2026. Its weatherization program covers air sealing, insulation and efficient heating, cooling and water heating equipment, and its page does not mention windows.
Do I need a home energy assessment before the Mass Save window rebate?
Yes. Your existing windows must be verified before the new ones are installed, and you must complete the weatherization recommendations from the assessment. Book the assessment first, then order windows.
Is the Gentek Series 9000 still tax credit eligible?
Not for windows installed in 2026, because the federal credit ended after 2025. The Series 9000 is ENERGY STAR Most Efficient, the level Mass Save asks for when replacing single-pane windows. Confirm the exact configuration is on the Mass Save qualified list before you buy.
Rebates come and go, but the measure is always free. Our free in-home quote puts the exact model, glass package and price in writing. You can check it against any program before you commit. Skip, Andrea or Gary reads every request, and we usually call back within one business day. You can also call (603) 764-7212, Monday to Friday 8:00 to 5:00.
Sources
- IRS: Energy Efficient Home Improvement Credit
- IRS FS-2025-05: FAQs for modification of sections 25C, 25D, 25E, 30C, 30D, 45L, 45W and 179D under Public Law 119-21
- ENERGY STAR: Windows and Skylights Federal Tax Credit
- Cape Light Compact (Mass Save sponsor): ENERGY STAR Most Efficient Windows rebate
- National Grid (Mass Save sponsor): Home Energy Assessments
- NHSaves: Energy Audits and Weatherization
- NHSaves: 2024–2026 Statewide Energy Efficiency Plan (PDF)
Header photo: Abner Jones House, Maple Street, Exeter – March 2026 by AntiCompositeNumber, licensed CC BY-SA 4.0, via Wikimedia Commons.
