§25C Home Improvement Credit 2026 Calculator
The Energy Efficient Home Improvement Credit (IRC §25C) gives homeowners 30% off energy-saving upgrades — capped at $1,200/year for most items plus a separate $2,000 cap for heat pumps. Calculate your total 2026 credit across all qualifying improvements.
| Heat pump credit (30%, cap $2,000) | — |
| Insulation credit (30%) | — |
| Windows credit (30%, cap $600) | — |
| Doors credit (30%, cap $250/door, $500 total) | — |
| Panel upgrade credit (30%, cap $600) | — |
| HVAC equipment credit (30%, cap $600) | — |
| Audit credit (30%, cap $150) | — |
| Subtotal before $1,200 annual cap | — |
| $1,200 annual cap applied | — |
| Total §25C credit (2026) | — |
The Energy Efficient Home Improvement Credit (IRC §25C) gives homeowners 30% of qualifying upgrade costs as a non-refundable federal tax credit, with two stacking caps: $1,200/year for most improvements and a separate $2,000/year for heat pumps and heat pump water heaters. The Inflation Reduction Act extended and expanded §25C through 2032, but the One Big Beautiful Bill of 2025 introduced potential phase-out provisions starting 2026.
How the §25C Caps Stack
The credit has nested per-item caps under the $1,200 umbrella: windows max $600, doors max $500 total ($250 each), home energy audit max $150, central AC/furnace/boiler max $600, electrical panel upgrade max $600. Insulation has no individual cap but still counts toward the $1,200 total. Heat pumps escape this entirely under their own $2,000 limit — meaning a household can legitimately claim up to $3,200/year in §25C credits when bundling a heat pump install with insulation upgrades.
Annual vs Lifetime Cap (Strategy Tip)
Critically, the $1,200 and $2,000 caps reset annually — they are NOT lifetime caps like the old §25C (pre-2023). Strategic homeowners spread major upgrades across two tax years: install a heat pump and audit in 2025, then windows and insulation in 2026. This doubles claimable credit from $3,200 to $6,400 across the two-year window. Plan installations to fall into separate tax years for maximum benefit.
Manufacturer Certification and PIN Requirements
Starting 2025, IRS requires Product Identification Numbers (PINs) for qualifying equipment — heat pumps, HVAC, water heaters. Each unit must be registered by a Qualified Manufacturer in the IRS Energy Credits Online portal. Without the manufacturer PIN on your tax return, the credit will be denied. Confirm PIN availability with installer BEFORE signing the install contract. Energy Star certification alone is insufficient — only IRS-registered manufacturers count.
Common §25C Filing Mistakes
(1) Missing the $150 audit cap — a Home Energy Audit by a certified auditor unlocks future credits and is itself credited up to $150 (30% of $500). (2) Confusing labor inclusion — labor for heat pumps and central HVAC is creditable; labor for insulation and windows is NOT. (3) Wrong filing year — credit applies in the year the property was placed in service, not when contracted or paid. (4) Forgetting PIN — see prior section. (5) Stacking with §25D wrong — solar and battery are §25D (separate credit, no $1,200 cap). Don't lump them on Form 5695 Part II.
Last updated May 2026. Sources: IRC §25C, IRS Form 5695 instructions, IRS FAQ Notice 2022-78. Confirm with a tax professional.