As of 19 May 2026

Federal 25C Tax Credit for Central AC and Heat Pumps in 2026

Section 25C of the Internal Revenue Code provides a non-refundable tax credit for residential energy efficiency improvements. For central air conditioning the cap is $600 per year. For heat pumps (including ducted air-source heat pumps that replace your AC) the cap is $2,000 per year. Both caps are 30 percent of installed cost, whichever is lower. The credit applies through tax year 2032.

25C Credit Caps and Lifetime Limits

Equipment Type	Credit Cap	Efficiency Threshold
Central AC (split system)	$600	SEER2 16+, EER2 12+ (south)
Central AC (package system)	$600	SEER2 16+, EER2 11+
Air-source heat pump (ducted)	$2,000	SEER2 16+, HSPF2 8.1+
Air-source heat pump (mini split)	$2,000	CEE highest tier
Geothermal heat pump	30% no cap	ENERGY STAR (under Section 25D)
Furnace (gas, propane, oil)	$600	AFUE 97+ (gas), AFUE 87+ (oil)
Heat pump water heater	$2,000	UEF 3.3+

Annual cap: $3,200 total (heat pumps and biomass stoves share the $2,000 sub-cap; everything else shares the $1,200 sub-cap). Reset every tax year through 2032.

CEE Highest Tier and AHRI Certification

The 25C credit references the Consortium for Energy Efficiency (CEE) highest tier efficiency specifications. CEE publishes regional efficiency tiers for HVAC equipment. The 25C credit picks up the highest published tier. For central split-system AC, this is currently SEER2 16.0 and EER2 12.0 (with some regional adjustments). For ducted air-source heat pumps, this is SEER2 16.0, EER2 12.0, and HSPF2 8.1 (slightly higher in cold-climate regions).

The matched system (outdoor unit + indoor coil + air handler) must be listed on the AHRI Directory with combined ratings meeting the threshold. AHRI certificates are paper documents (or PDF) that the installer obtains from AHRI's website using the model numbers of your specific equipment combination. Keep the certificate with your tax records as supporting documentation if the IRS requests proof of qualification.

The installer is responsible for confirming the system qualifies before install. If the installer cannot produce the AHRI certificate showing the threshold is met, the system likely does not qualify and you cannot claim the credit. Get this in writing before signing the install contract for any quote that depends on the 25C credit for budget approval.

Form 5695 Walk-Through

IRS Form 5695, Residential Energy Credits, is the form used to claim the 25C credit. The form has two parts: Part I (Residential Clean Energy Credit, Section 25D, solar, geothermal, fuel cell, wind, battery) and Part II (Energy Efficient Home Improvement Credit, Section 25C, what we are discussing). Part II has line items for specific equipment categories.

For central AC: enter the cost on Line 22a (Energy Efficient Air Conditioner). Calculate 30 percent (Line 22b). Apply the $600 cap if needed. For heat pump: enter the cost on Line 29a (Heat Pumps and Heat Pump Water Heaters). Calculate 30 percent (Line 29b). Apply the $2,000 cap if needed. Both amounts flow to Line 32 (total credit for the year) and transfer to your Form 1040 Schedule 3 Line 5b, then to Form 1040 Line 22 to reduce your federal tax owed.

Most tax software (TurboTax, H&R Block, Free File providers) walks through Form 5695 with prompts that guide you through equipment type, cost, and qualification questions. Manual paper filing requires reading the IRS Form 5695 Instructions document (typically 8 to 12 pages) and the supporting worksheets.

Stacking 25C with State and Utility Programs

25C stacks freely with state energy credits, utility rebates, and grant programs. Important: the cost basis for the federal 25C 30 percent calculation is the gross cost before utility rebates and state grants. State tax credits also typically use the gross cost basis. Only the manufacturer's straight-discount on equipment reduces the basis.

Example stack: Massachusetts homeowner installs a $9,000 cold-climate heat pump. Mass Save rebate: $6,000. Federal 25C credit basis: $9,000. Federal 25C credit: 30 percent of $9,000 = $2,700, capped at $2,000. Total recovery: $6,000 + $2,000 = $8,000 on a $9,000 install. Net out-of-pocket: $1,000. The math is genuinely transformative for households doing the right configurations in the right states.

Stacking-eligible state programs by region: California TECH Clean California, Massachusetts Mass Save, New York Clean Heat, Maine Efficiency, Vermont Efficiency Vermont, Oregon Energy Trust, Washington Energy Smart, Colorado Xcel Home Energy, Minnesota CARD program.

Common Mistakes That Disqualify the Credit

Equipment-only swap with non-matched coil. The 25C credit requires the matched system (outdoor + indoor) to meet the efficiency threshold. Installing a high-SEER2 outdoor unit with an old low-efficiency indoor coil may not qualify because the combined AHRI-certified rating drops below the threshold. Always confirm the AHRI certificate covers the matched system you are actually installing.

Used equipment. The 25C credit only applies to new equipment placed in service in the tax year. Used or refurbished equipment, even if it meets efficiency thresholds, does not qualify.

Rental property. The 25C credit is limited to your principal residence. Rental properties, second homes, and vacation rentals do not qualify (different commercial energy efficiency provisions may apply).

Equipment without AHRI certification. Some off-brand or grey-market equipment is not registered with AHRI. If your installer cannot produce an AHRI certificate, the equipment cannot be claimed under 25C even if it meets the published SEER2 numbers.

All Rebates and Credits SEER2 Threshold Detail R-454B Refrigerant Transition 3 Ton Install (25C eligible)MA Mass Save Stack CA TECH Stack

From the portfolio: solar panel install cost (Section 25D credit, no cap).

Frequently Asked Questions

What is the Section 25C tax credit?

Section 25C of the Internal Revenue Code allows a non-refundable tax credit for qualifying residential energy efficiency improvements. The credit is 30 percent of the installed cost, capped per equipment type. Central AC cap: $600. Heat pump cap: $2,000. The credit was renewed and expanded by the Inflation Reduction Act of 2022 and applies through tax year 2032.

What does 'non-refundable' mean for the credit?

The credit reduces your tax liability dollar-for-dollar but cannot generate a refund beyond zero. If you owe $400 in federal income tax and qualify for the $600 AC credit, your tax liability drops to zero but the unused $200 does not roll over to next year or refund. For most middle-income households this is not a binding constraint. Low-income households with minimal tax liability may not capture the full credit.

How do I know my system qualifies?

Two requirements: efficiency threshold (typically CEE highest tier, SEER2 16+ and EER2 12+ for central AC, with regional variations for heat pumps) and AHRI certification (the matched indoor/outdoor system must be listed on the AHRI Directory). Your installer should provide the AHRI Certificate Number. Equipment that meets the threshold typically displays an ENERGY STAR Most Efficient label.

When do I claim the credit?

In the tax year the system is placed in service (not the year you paid the contractor or the year you ordered the equipment). 'Placed in service' usually means the install is complete and the system is functional. File IRS Form 5695 with your federal return. The credit reduces your tax owed on Line 22 of Form 1040 via the schedule transfer.

Can I stack 25C with utility rebates and state programs?

Yes. The federal 25C credit is separate from utility rebates, state tax credits, and state grant programs. They all stack. The only caveat: the cost basis for the 25C credit is the gross cost before utility rebate. So if your install was $5,500 gross, your utility paid you $700 rebate, and you got $600 federal credit, you have effectively recovered $1,300 of the $5,500 total cost, but Form 5695 uses $5,500 not $4,800 as the basis for the 30 percent calculation.

Does a heat pump always qualify for $2,000?

Most do but not all. The heat pump must meet CEE highest tier or the equivalent ENERGY STAR Most Efficient designation. For ducted heat pumps this typically means SEER2 16+ and HSPF2 8.1+ for southern climates, slightly higher thresholds in cold climates. Many entry-tier heat pumps fall below the threshold. Verify with the AHRI Certificate before assuming the $2,000 cap applies. Mid-tier and premium heat pumps from Carrier, Trane, Lennox, Daikin, and Mitsubishi typically qualify; budget single-stage units sometimes do not.