Geothermal Heat Pumps Still Have a 30% Federal Tax Credit in 2026 — Here's What Homeowners Need to Know

When the Section 25C federal tax credit for air-source heat pumps expired on December 31, 2025, many homeowners assumed all HVAC tax incentives were gone. They are not. Ground-source heat pumps — also called geothermal heat pumps — remain eligible for a 30 percent federal tax credit under Section 25D through 2032, and that credit applies to the full installed cost including the ground loop.

This distinction matters enormously for homeowners considering a geothermal system. On a $40,000 geothermal installation, the 30 percent credit returns $12,000 in tax relief — making geothermal significantly more financially accessible in 2026 than many homeowners realise. Here is the complete guide to how the credit works, who qualifies, and what a geothermal system actually involves.

How the Section 25D Geothermal Credit Works

The Section 25D Residential Clean Energy Credit provides a 30 percent nonrefundable tax credit for qualifying geothermal heat pump property installed in a US home. The specific rules:

• Credit amount: 30% of all qualifying costs, with no dollar cap. This is the most generous aspect of 25D relative to the expired 25C credit, which was capped at $2,000 for heat pumps. A $45,000 geothermal installation generates a $13,500 credit under 25D — far above what 25C could have provided.

• What qualifies: Equipment that meets the Energy Star geothermal heat pump requirements and is installed in a US residential property — primary residence or secondary home. Both the heat pump equipment and the ground loop installation costs qualify.

• Nonrefundable but carryforward eligible: The 25D credit is nonrefundable — it can reduce your federal tax liability to zero but does not generate a refund if the credit exceeds your tax liability. However, unused credit can be carried forward to future tax years, making it accessible even for homeowners whose current-year tax liability is smaller than the credit amount.

• Owner-occupied requirement: The property must be used as a residence. Investment properties and properties used exclusively as rental properties do not qualify for the residential 25D credit.

• Available through 2032: Unlike the 25C credit that was cut short by the One Big Beautiful Bill Act, the 25D geothermal credit remains in effect through December 31, 2032 — giving homeowners nearly a decade to plan and execute a geothermal installation at the current credit rate.

The Section 25D Residential Clean Energy Credit provides a 30% federal tax credit — with no dollar cap — for qualifying geothermal heat pump installations including ground loop costs, available through December 31, 2032. On a $40,000 geothermal installation, the 30% credit generates $12,000 in tax relief — significantly more than the expired Section 25C air-source heat pump credit could have provided.

What a Geothermal System Actually Costs in 2026

Geothermal heat pump system costs have a wide range because the ground loop installation cost varies significantly based on soil conditions, available land, and the specific loop configuration:

• Vertical bore ground loop (most common, smallest land footprint): Borehole drilling costs $15 to $25 per foot, and most residential systems require 150 to 400 feet of borehole per ton of heat pump capacity. For a 3-ton system requiring 600 feet of borehole at $20 per foot, the ground loop alone costs $12,000. Total system cost including the heat pump unit and installation typically runs $30,000 to $50,000.

• Horizontal ground loop (requires significant land area): Trenching is less expensive than drilling — typically $800 to $1,500 per ton of capacity for the loop installation. A 3-ton horizontal system's ground loop might cost $2,400 to $4,500. Total system cost including equipment: $20,000 to $35,000.

• Pond or lake loop (if water body available): The least expensive ground loop option if a suitable water body is accessible — typically $500 to $1,000 per ton. Total system cost including equipment: $18,000 to $28,000.

After applying the 30% Section 25D credit, the net costs are:

• Vertical bore system net cost after credit: $21,000 to $35,000

• Horizontal loop system net cost after credit: $14,000 to $24,500

At these net costs, geothermal is significantly more expensive upfront than an air-source heat pump ($9,000 to $15,000 installed before any credits). The financial case depends on the operating cost savings over the life of the system — which at current energy prices and geothermal's efficiency advantage can be compelling over a 15 to 20 year system life.

When Geothermal Makes Financial Sense

The financial case for geothermal is strongest when several conditions align:

• You heat primarily with electric resistance or oil: The operating cost savings from replacing electric resistance heating with geothermal are very large — geothermal delivers 3 to 5 units of heat per unit of electricity consumed versus 1 unit from electric resistance. If you currently pay $3,000 per year to heat with electric baseboard heaters, geothermal might reduce that to $800 to $1,000.

• You live in a cold climate and are replacing gas with heat pump: In cold climates where gas heat is the alternative, the operating cost comparison is tighter. But geothermal's higher COP at extreme outdoor temperatures versus air-source heat pumps makes it more competitive in very cold regions.

• You plan to stay in the home long-term: The 30% federal credit reduces the upfront cost, but geothermal's payback period through energy savings is typically 8 to 15 years. Homeowners who plan to sell within 5 years may not fully recover the investment.

• You have suitable ground conditions and land: Not all sites are suitable for all loop configurations. A soil report or geological assessment from a qualified geothermal installer is an important early step — before you invest in quotes and planning.

Frequently Asked Questions

Is there still a tax credit for geothermal heat pumps?

Yes. The Section 25D Residential Clean Energy Credit provides a 30% federal tax credit for qualifying geothermal heat pump installations through December 31, 2032. Unlike the expired Section 25C credit for air-source heat pumps, the 25D geothermal credit has no dollar cap and covers the full installed cost including ground loop installation.

How much does a geothermal heat pump system cost after the tax credit?

A vertical bore geothermal system typically costs $30,000 to $50,000 installed. After the 30% Section 25D federal tax credit, the net cost is $21,000 to $35,000. Horizontal loop systems cost $20,000 to $35,000 installed, with a net cost of $14,000 to $24,500 after the credit.

How does the geothermal 25D credit differ from the 25C heat pump credit?

The Section 25D geothermal credit provides 30% of total installed cost with no dollar cap, is available through 2032, and covers ground loop installation costs. The Section 25C credit for air-source heat pumps was capped at $2,000 and expired December 31, 2025. On a large geothermal installation, the 25D credit can return $10,000 to $15,000 or more in tax relief.

Is geothermal worth it in 2026?

Geothermal is most financially compelling for homeowners replacing electric resistance or oil heating, living in cold climates where air-source heat pump performance drops, planning to stay in the home for 10 or more years, and having suitable ground conditions for an efficient loop configuration. The 30% federal tax credit significantly improves the payback economics compared to full-cost purchases.