Energy Star windows and skylights installed by December 31, 2025 qualify for a federal tax credit: 30% of your costs, up to $600.
Credit Expired December 31, 2025
The 25C Energy Efficient Home Improvement Credit expired on December 31, 2025 due to the "One Big Beautiful Bill" (Public Law 119-21). If you installed qualifying windows or skylights by that date, you can still claim the credit on your 2025 tax return. (IRS FAQ on Public Law 119-21)
Quick Summary
- Windows and skylights go on Form 5695, Part II, Section A, Line 20
- Credit: 30% of costs, maximum $600 total
- Must meet Energy Star certification requirements
- Main home only (not rentals, not second homes)
- Part of the $1,200 annual cap shared with insulation, doors, etc.
What Qualifies
Energy Star Required
Windows and skylights must meet Energy Star certification requirements for your climate zone. Not all windows qualify, even if they're new.
Qualifying products:
- Exterior windows (including storm windows)
- Skylights
- Glazing materials (replacement glass for existing windows)
Requirements:
- Must be Energy Star certified for your climate zone
- Installed in your main home in the United States
- You must be the original user
- Components must remain in use for at least 5 years
Main Home Only
Unlike heat pumps and water heaters, windows and skylights only qualify if installed in your principal residence. Second homes, vacation properties, and rental properties don't qualify for the window credit.
Credit Amount
The credit is 30% of your costs, capped at $600 total.
Tax Credit Calculator
This calculator provides an estimate. Your actual credit may vary based on your tax situation. The credit is non-refundable and cannot exceed your tax liability.
Example calculations:
| Total Cost | 30% Calculation | Actual Credit |
|---|---|---|
| $1,500 | $450 | $450 |
| $2,000 | $600 | $600 (capped) |
| $3,000 | $900 | $600 (capped) |
Once you hit $2,000 in costs, you've maxed out the credit. Spending more doesn't increase what you get back.
What's Included
Yes, covered
- Window units (frames and glazing)
- Skylight units
- Installation labor
- Materials required for installation
- Storm windows (when Energy Star certified)
No, not covered
- Window screens
- Interior window treatments (blinds, shades)
- Decorative glass features beyond Energy Star specs
- Repairs to existing windows
Labor is included. The 30% covers both the window products and what you paid the contractor to install them.
Form 5695 Line 20 Instructions
Windows and skylights are reported in Part II, Section A, Line 20 of Form 5695.
Lines 17a-17e: Qualifying Questions
Before filling in Line 20, you must answer the qualifying questions in Lines 17a-17e. All Section A improvements (insulation, doors, windows) require these answers.
- 17a: Are improvements installed in your main home in the US? (Yes required)
- 17b: Are you the original user? (Yes required)
- 17c: Will components remain in use for at least 5 years? (Yes required)
- 17d: Enter your main home address
- 17e: Were improvements related to construction? (If Yes, only post-construction improvements qualify)
Line 20a: Four Most Expensive Windows/Skylights
Enter the QMID and cost of your four most expensive qualifying windows or skylights.
Two pieces of information:
- QMID boxes: Enter the manufacturer's 4-character QMID code
- Cost field: Enter the total cost of those four units (equipment + installation)
The QMID is a 4-character alphanumeric code that identifies your equipment manufacturer. Enter it exactly as shown in the IRS database or our directory.
Find your window manufacturer's QMID in our directory. Look for the brand name on your window label or installation documents.
Note
The form provides space for four windows because the IRS wants to track high-cost items separately. If you only installed one or two windows, enter those costs here and leave the remaining spaces blank.
Line 20b: All Other Qualifying Windows
If you installed more than four windows or skylights, enter the combined cost of the remaining units here.
Example: You installed 10 windows total.
- Line 20a: Cost of the 4 most expensive windows + their QMID
- Line 20b: Cost of the other 6 windows
Line 20c: Total Window Costs
Add Line 20a and Line 20b. This is your total qualifying window expenditure.
Line 20d: Credit Calculation
Multiply Line 20c by 30% (0.30). Maximum credit is $600.
If your calculation exceeds $600, enter $600.
Example:
- Line 20c: $2,500
- Calculation: $2,500 × 0.30 = $750
- Line 20d: $600 (capped)
Part of the $1,200 Cap
The $600 window credit counts toward a larger annual limit of $1,200 for all Section A and most Section B improvements.
Items Sharing the $1,200 Annual Cap
| Equipment | Credit Limit | Notes |
|---|---|---|
| Windows/Skylights | $600 | 30% of cost, Line 20 |
| Doors (exterior) | $500 | 30% of cost, Line 19 |
| Insulation | $1,200 | 30% of cost, Line 18 |
| Central AC | $600 | 30% of cost, Line 22 |
| Gas Furnace/Boiler | $600 | 30% of cost, Line 24 |
| Gas/Oil Water Heater | $600 | 30% of cost, Line 23 |
| Electrical Panel | $600 | 30% of cost, Line 25 |
| Home Energy Audit | $150 | 30% of cost, Line 26 |
Combined maximum for these items: $1,200 annually. Heat pumps have a separate $2,000 cap on Line 29.
Example scenario:
- Installed windows: $600 credit (Line 20)
- Installed new exterior doors: $500 credit (Line 19)
- Installed insulation: $400 credit (Line 18)
- Total calculated: $1,500
- Actual credit: $1,200 (capped at Line 28)
Form 5695 Line 28 enforces this limit. You add all the credits from Section A and Lines 22-26, then cap the total at $1,200.
Energy Star Certification
Not all windows meet the requirements. Energy Star certification varies by climate zone.
Check Before You Buy
Before purchasing windows, verify they're Energy Star certified for your climate zone. Ask your contractor or check the Energy Star label on the product.
Energy Star defines climate zones based on heating and cooling degree days. Your location determines which efficiency thresholds your windows must meet.
Key ratings for windows:
- U-Factor: Heat transfer rate (lower is better)
- SHGC: Solar Heat Gain Coefficient (optimal value varies by climate)
Northern climates: Low U-Factor (good insulation), flexible SHGC Southern climates: Low SHGC (blocks heat gain), moderate U-Factor
Search certified windows and skylights by manufacturer
ENERGY STARClaiming the Credit
Gather Documentation
- Invoice showing window models, installation date, and costs
- Energy Star certification label or certificate
- Manufacturer's QMID code (find in our directory)
- Payment confirmation
Complete Form 5695 Section A
- Lines 17a-17e: Answer qualifying questions
- Line 20a: QMID and cost of 4 most expensive windows
- Line 20b: Cost of other qualifying windows
- Line 20c: Total costs
- Line 20d: Multiply by 30%, max $600
Calculate Section A Total
- Line 27: Add all Section A and B credits (Lines 18b, 19h, 20d, 22d-26c)
- Line 28: Enter lesser of Line 27 or $1,200
- Add Line 29h (heat pumps, if applicable)
- Line 30: Total credit
Transfer to Form 1040
- Line 32 from Form 5695 goes to Schedule 3, line 5b
- Credit reduces tax liability dollar-for-dollar
Common Mistakes
Avoid These Errors
Using non-Energy Star windows: Regular windows don't qualify. Verify certification before purchase.
Claiming rental or second home: Only your principal residence qualifies for the window credit.
Missing the QMID: Starting in 2025, the QMID is required. Look it up in our directory or call the manufacturer.
Including screens and blinds: Only the window unit and installation labor count. Accessories don't qualify.
Forgetting the $1,200 cap: Windows share a $1,200 annual limit with doors, insulation, AC, furnaces, and more.
Not subtracting rebates: If you received manufacturer or utility rebates, subtract them from your costs before calculating the credit.
Stacking With Other Improvements
You can claim windows along with other energy improvements in the same year, subject to the overall limits.
Example: Full envelope upgrade
- Windows: $2,500 installed → $600 credit (Line 20d)
- Exterior doors: $1,800 installed → $500 credit (Line 19h, capped)
- Insulation: $1,500 installed → $450 credit (Line 18b)
- Section A total before cap: $1,550
- Actual Section A credit: $1,200 (Line 28, capped)
If you also installed a heat pump:
- Heat pump: $7,000 installed → $2,000 credit (Line 29h)
- Combined total credit: $3,200 ($1,200 Section A + $2,000 Line 29)
The $3,200 is the maximum total credit you can claim in a year for all Part II improvements.
Timeline and Expiration
Installation Deadline Passed
The 25C credit expired December 31, 2025. Installations after that date do not qualify. If you installed qualifying windows by December 31, 2025, you can still claim the credit on your 2025 tax return (filed in 2026).
Active period: January 1, 2023 through December 31, 2025
The installation date matters, not the purchase date. If you bought windows in 2025 but installed them in 2026, they don't qualify.
Non-Refundable Credit
The 25C credit is non-refundable. It can reduce your tax liability to zero but won't generate a refund beyond what you've already paid in withholding.
Example:
- You owe $400 in federal taxes
- Your window credit is $600
- You reduce your taxes to $0
- The extra $200 doesn't carry forward or refund
Note
If you typically get a large refund (meaning you've overpaid through withholding), you'll likely be able to use the full credit. If you typically owe at filing time, plan accordingly.
Record Keeping
Keep these documents for at least 3 years after filing:
- Completed Form 5695
- Contractor invoice (itemized with installation date)
- Energy Star certification label or certificate
- Payment records
- QMID source documentation
- Window manufacturer specifications
The IRS can audit returns up to 3 years after filing. Clean records prevent headaches.
Getting Your QMID
Starting with the 2025 tax year, you need your window manufacturer's QMID — a 4-character IRS registration code. It won't be on your windows or your invoice. Look it up in our QMID directory by manufacturer name, or call the manufacturer and ask.
Official Resources
IRS overview of the Energy Efficient Home Improvement Credit
IRS.govDownload the form and instructions directly from the IRS
IRS.govSearch certified windows and skylights by manufacturer
ENERGY STAR