The federal Residential Clean Energy Credit (Section 25D) ended for expenditures made after December 31, 2025, and the IRS treats an expenditure as made when installation is completed (IRS FS-2025-05). Federal tax credits for this work have ended, but state, local and utility rebates may still apply; check what is available at your address with the DuloCore rebate calculator.
What is the residential geothermal tax credit and how much money can you get?
The federal Residential Clean Energy Credit (Section 25D) ended for expenditures made after December 31, 2025, and the IRS treats an expenditure as made when installation is completed (IRS FS-2025-05). The credit applies to equipment, labor, piping, and on-site preparation work completed in tax year 2026 or later. Form 5695 only covers qualifying work completed by December 31, 2025 and claimed on a 2025 return; the federal 25C and 25D credits ended after that date (IRS FS-2025-05).
So what does "no upper limit" mean in practice? A $25,000 geothermal installation generates a $7,500 credit. A $40,000 system yields $12,000. And unlike the old Section 25D credit that expired January 1, 2026, the IRA framework removes lifetime caps—homeowners can claim the credit for multiple properties or system replacements as long as each qualifies independently.
But the 30% rate phases down after 2032. Systems placed in service during 2033 qualify for 26%, dropping to 22% in 2034, before the credit sunsets entirely in 2035 unless Congress extends the program. So timing installation before 2033 maximizes federal savings.
The credit applies only to existing homes or new construction where the homeowner occupies the property. And vacation homes qualify if used personally more than 14 days per year or 10% of rental days, whichever is greater.
"Geothermal heat pumps use the constant temperature of the earth as the exchange medium instead of the outside air temperature." — U.S. Department of Energy
Are you eligible for the geothermal tax credit in 2026?
The federal Residential Clean Energy Credit (Section 25D) ended for expenditures made after December 31, 2025, and the IRS treats an expenditure as made when installation is completed (IRS FS-2025-05). The system must meet Energy Star specifications and serve a dwelling unit located in the United States. Renters and landlords of rental properties don't qualify unless the owner occupies the property.
Tax liability matters because the credit is nonrefundable—it reduces what you owe the IRS to zero but doesn't generate a refund check. But unused credit carries forward to future tax years indefinitely until fully claimed. So a homeowner owing $5,000 in 2026 taxes who earns a $7,500 credit pays zero in 2026 and carries $2,500 forward to 2027.
And income limits don't apply. The geothermal credit has no modified adjusted gross income (MAGI) cap, unlike the energy tax credits for energy-efficient windows or insulation that phase out at higher earnings.
Installation must occur between January 1, 2026, and December 31, 2032, for the full 30% rate. So signing a contract in 2025 but completing installation in January 2026 qualifies for the 2026 tax year credit.
How do you document your geothermal system for tax credit approval?
Form 5695 only covers qualifying work completed by December 31, 2025 and claimed on a 2025 return; the federal 25C and 25D credits ended after that date (IRS FS-2025-05). The IRS doesn't require documentation submission with the return but audits demand proof, so contractors should provide a Manufacturer's Certification Statement listing equipment model numbers, efficiency ratings, and Energy Star certification numbers.
Itemized invoices must separate equipment costs from labor, site preparation, and materials. And keep receipts for ductwork modifications, electrical panel upgrades, and drilling costs—all qualify as installation expenses under IRS guidelines.
But the IRS specifically excludes certain costs. Landscaping repairs, cosmetic upgrades, and financing interest don't count toward the credit base. So a $30,000 project with $2,000 in landscaping restoration yields a credit on $28,000, not the full amount.
Contractor licensing matters in some states. California requires geothermal installers to hold C-61/D-07 or C-10 licenses. And unlicensed work risks credit denial if audited, even if the system itself qualifies.
Store documentation for at least seven years after filing. Or use DuloCore's free rebate calculator to estimate your total savings from federal credits and California state programs before starting your project.
What are the stacking rules when combining geothermal credits with other energy incentives?
The federal geothermal tax credit stacks with state rebates, utility incentives, and local tax exemptions without reducing the credit base, but manufacturer rebates and point-of-sale discounts lower the qualified installation cost used to calculate the 30% credit. The IRS treats utility rebates as non-taxable incentives that don't offset the credit, while manufacturer cashback programs reduce the homeowner's out-of-pocket cost before applying the percentage.
So here's how stacking works in practice: A $25,000 geothermal system with a $2,000 utility rebate and $1,000 manufacturer discount nets $22,000 in qualified costs for the federal credit. The homeowner claims 30% of $22,000 ($6,600), not 30% of $25,000. But the $2,000 utility rebate doesn't count as taxable income.
And California's TECH Clean California program offers point-of-sale rebates for heat pump installations—those reduce the credit base too. So a $20,000 system with a $3,000 TECH rebate qualifies for 30% of $17,000 ($5,100) in federal credits.
But local property tax exemptions stack freely. Many California counties exempt geothermal equipment from property tax reassessment under Revenue and Taxation Code Section 73. That saves $200-$500 annually without touching the federal credit.
What's the application process and what are the critical deadlines?
Form 5695 only covers qualifying work completed by December 31, 2025 and claimed on a 2025 return; the federal 25C and 25D credits ended after that date (IRS FS-2025-05). The system must be "placed in service" by December 31 of the claim year, meaning operational and delivering heating or cooling, not just contracted or partially installed.
So signing a contract in November 2026 but finishing installation in February 2027 means claiming the credit on your 2027 tax return filed by April 15, 2028. And the IRS defines "placed in service" as the date the system starts operating, not when final payment clears.
But amended returns work too. Homeowners who forgot to claim the credit can file Form 1040-X within three years of the original filing deadline. So a 2026 installation claimed late must be amended by April 15, 2030.
And there's no separate application, no state agency approval, no inspection requirement before filing. Form 5695 only covers qualifying work completed by December 31, 2025 and claimed on a 2025 return; the federal 25C and 25D credits ended after that date (IRS FS-2025-05).
How does the geothermal tax credit compare to other home energy incentives?
The geothermal tax credit offers the highest percentage rate (30%) and no dollar cap among federal home energy incentives, while heat pump (these federal credits ended for projects completed after December 31, 2025) rebates from state and utility programs provide smaller upfront discounts but don't require tax liability to claim. The federal Energy Efficient Home Improvement Credit (Section 25C) ended for property placed in service after December 31, 2025 (IRS FS-2025-05). (Note: Federal tax credit percentages and availability are subject to change; the 30% Residential Clean Energy Credit under Section 25D expired December 31, 2025. Verify current incentives at energy.gov.)
So a $25,000 geothermal system claims $7,500 federally. A $6,000 air-source heat pump maxes out at $2,000. And a $4,000 insulation project caps at $1,200. But air-source systems install faster (3-5 days vs. 2-3 weeks for geothermal) and cost less upfront ($5,000-$8,000 vs. $15,000-$30,000).
And state programs vary wildly. California's TECH Clean California offers $3,000-$7,000 for heat pump water heaters but nothing for geothermal. But property-assessed clean energy (PACE) financing covers geothermal in 38 California counties, spreading costs over 20 years on property tax bills.
Or compare payback periods: Geothermal systems save $1,200-$2,400 annually on energy bills in cold climates, reaching break-even in 7-10 years after credits. Air-source heat pumps save $600-$1,000 annually with 5-8 year payback.
Official Sources
- U.S. Department of Energy: Geothermal Heat Pumps — Technical overview of ground-source heat pump technology and efficiency ratings
- IRS: Energy Efficient Home Improvement Credit — Official tax credit guidance, Form 5695 instructions, and qualified expenditure definitions (note: the federal 25C and 25D credits ended for projects completed after December 31, 2025)
- ENERGY STAR: Geothermal Heat Pumps — Certification requirements and qualified product database
Related Reading: Learn more about Is The Geothermal Tax Credit Still Available and Solar Rebate Vs Tax Credit Difference.
Frequently Asked Questions
Who is eligible for the residential geothermal tax credit?
The federal Residential Clean Energy Credit (Section 25D) ended for expenditures made after December 31, 2025, and the IRS treats an expenditure as made when installation is completed (IRS FS-2025-05). Renters, landlords of rental properties, and commercial building owners don't qualify unless the property serves as the owner's dwelling unit.
What is the maximum amount you can claim for a geothermal system?
The federal Residential Clean Energy Credit (Section 25D) ended for expenditures made after December 31, 2025, and the IRS treats an expenditure as made when installation is completed (IRS FS-2025-05). A $50,000 system generates a $15,000 credit. And unused credit carries forward indefinitely to future tax years until fully claimed against tax liability.
How do you claim the residential geothermal tax credit on your taxes?
Form 5695 only covers qualifying work completed by December 31, 2025 and claimed on a 2025 return; the federal 25C and 25D credits ended after that date (IRS FS-2025-05). Retain manufacturer certifications and itemized invoices for at least seven years in case of audit.
When is the deadline to install a geothermal system for the tax credit?
Geothermal systems must be placed in service (operational and delivering heating or cooling) by December 31 of the tax year to claim the credit on that year's return. The federal Residential Clean Energy Credit (Section 25D) ended for expenditures made after December 31, 2025, and the IRS treats an expenditure as made when installation is completed (IRS FS-2025-05).
What is the difference between the geothermal tax credit and other HVAC rebates?
The geothermal tax credit is a federal nonrefundable credit requiring tax liability to claim, while HVAC rebates from state and utility programs provide upfront point-of-sale discounts with no tax filing required. The geothermal credit offers 30% with no cap; state rebates max out at $3,000-$7,000 but don't depend on annual income or tax owed.
Ready to calculate your total savings? Use our free rebate calculator to estimate federal tax credits, California state rebates, and utility incentives for your geothermal installation—plus compare payback periods across different system types.
Updated: April 14, 2026 — fact-checked by DuloCore Research. About our editorial process.
Check your California heat pump rebate eligibility — see the programs you qualify for and the dollar amounts on our California heat pump rebate finder.