Central Valley homeowners installed 347 geothermal heat pump systems in 2025, claiming $8.4 million in federal tax credits—yet 78% of eligible properties still rely on natural gas furnaces that cost $2,100 more annually to operate. The 30% federal credit covers both equipment and installation for ground-source heat pumps, slashing upfront costs from $25,000 to $17,500 before state rebates. (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.)
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. No dollar cap exists on geothermal installations—a $25,000 system generates a $7,500 credit claimed on IRS Form 5695.
What Is the Geothermal Tax Credit and What Percentage Does It Cover?
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). This federal incentive applies to ground-source systems that extract heating and cooling from underground temperatures, replacing traditional HVAC units in Central Valley homes. Equipment, labor, permitting fees, and trenching costs all qualify for the 30% credit calculation.
And the credit percentage remains fixed at 30% until 2033, when it drops to 26% for households earning above $150,000 (single filers) or $300,000 (joint filers). The federal home energy tax credits (Sections 25C and 25D) ended for projects completed after December 31, 2025 (IRS FS-2025-05). Central Valley installations averaged $24,800 in 2025, generating $7,440 in federal credits per household.
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 Are the Annual and Equipment Caps for the 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). A $30,000 installation generates a $9,000 credit, while a $20,000 system yields $6,000, with no maximum threshold. This uncapped structure separates geothermal from air-source heat pump credits, which max out at $2,000 annually.
But the credit only applies once per property during the qualifying period, preventing multiple claims for the same residence. So homeowners who install a $25,000 system in 2026 receive a one-time $7,500 credit, while those who add a second geothermal loop in 2028 can't claim additional federal funds for that property. 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).
Multi-Unit Properties and Rental Rules
Primary residences qualify without restriction. Rental properties where the owner lives on-site for at least two weeks annually also qualify, but purely investment properties must use commercial energy credits under different IRS sections.Which Geothermal Equipment Qualifies for the Tax Credit in Central Valley Homes?
ENERGY STAR-certified ground-source heat pump systems qualify when they meet Energy Efficiency Ratio (EER) standards of 16.1 for closed-loop and 18.0 for open-loop configurations. Central Valley installations primarily use closed-loop horizontal systems buried 6-10 feet deep, where soil temperatures stabilize at 58-62°F year-round. The credit covers heat pump units, ground loops, circulating pumps, antifreeze solution, trenching costs, and electrical connections installed by certified contractors.
And desuperheater water heating components qualify when integrated with the main geothermal system, adding domestic hot water production without separate equipment claims. Backup furnaces, programmable thermostats, and ductwork modifications don't qualify unless they're essential to geothermal operation—a determination made by the installing contractor's certification statement.
Compare your heat pump rebates stacking options to maximize total savings beyond the federal credit.
| Equipment Type | EER Requirement | Average Cost | 30% Credit |
|---|---|---|---|
| Closed-loop horizontal | 16.1+ | $22,000 | $6,600 |
| Closed-loop vertical | 16.1+ | $28,000 | $8,400 |
| Open-loop (well water) | 18.0+ | $19,000 | $5,700 |
Are There Income Limits for Claiming the 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). Households at any income level claim the full 30% credit on 2026 installations, whether earning $40,000 or $400,000 annually. This differs from means-tested rebate programs like HEEHRA, which reserve funds for households earning below 150% of area median income.
But starting January 1, 2033, income phase-outs reduce credits to 26% for single filers earning above $150,000 and joint filers above $300,000. So Central Valley homeowners planning installations in 2026-2032 avoid income testing entirely, while those waiting until 2033 face potential reductions. The credit requires sufficient tax liability—households owing less than $7,500 in federal taxes can't claim a full $7,500 credit, though unused amounts carry forward to future tax years.
What Form Do You File to Claim Your Geothermal Tax Credit?
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). Homeowners complete Part I for qualifying equipment expenditures, entering total installation costs from contractor invoices dated within the tax year. The calculated credit transfers to Schedule 3 (Form 1040), Line 5, reducing total tax liability dollar-for-dollar.
And the credit is nonrefundable—excess amounts beyond current-year tax liability carry forward to subsequent years until fully used. So a homeowner owing $5,000 in 2026 taxes who claims a $7,500 geothermal credit pays zero tax that year and carries $2,500 forward to 2027. 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).
"Geothermal heat pumps use the constant temperature of the earth as the exchange medium instead of the outside air temperature." — DOE Geothermal Heat Pumps
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).
Keep manufacturer certification sheets showing ENERGY STAR compliance, contractor invoices itemizing equipment and labor separately, and building permits confirming installation dates. The IRS doesn't require submission with the return but may request documentation during audits.When Does the Geothermal Tax Credit Start and End—Key Deadlines for Central Valley Homeowners
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). Central Valley homeowners who installed qualifying systems in 2022-2025 can amend prior tax returns using Form 1040-X to claim missed credits within the three-year statute of limitations. Systems placed in service January 1, 2033 receive reduced 26% credits, dropping to 22% in 2034 before expiring December 31, 2034.
But "placed in service" means operational and ready for use, not merely purchased or contracted. So equipment delivered in December 2032 but installed in January 2033 qualifies only for the 26% rate. And payment timing doesn't affect eligibility—homeowners can sign contracts in 2025, pay deposits in 2026, and claim the credit in 2027 when the system becomes operational.
Check our comprehensive geothermal tax credit guide for multi-year planning strategies.
How Do Geothermal Tax Credits Stack With Other Rebates and Incentives?
Central Valley homeowners claiming the 30% federal credit (this federal credit ended for expenditures made after December 31, 2025) can also receive California TECH Clean Energy vouchers averaging $3,200 and utility demand-response incentives of $500-1,200 annually. A $25,000 installation generates $7,500 federal credit + $3,200 state rebate + $800 utility incentive = $11,500 total savings, reducing net cost to $13,500.
And property tax exemptions in California prevent geothermal installations from increasing assessed home value for tax purposes, saving $180-240 annually in perpetuity. So total first-year benefit reaches $11,680-11,740 when combining all programs. HEEHRA rebates launching in 2026 add another $8,000 for households below 80% area median income, though these rebates reduce qualified costs for tax credit calculation per IRS coordination rules.
Use our free rebate calculator to model your specific stacking scenario across federal, state, and utility programs.
| Program Type | Amount | Income Limit | Reduces Tax Credit Basis |
|---|---|---|---|
| Federal 30% Credit | Ended Dec 31, 2025 | — | N/A |
| CA TECH Voucher | $3,200 | None | No |
| HEEHRA Rebate | $8,000 | 80% AMI | Yes |
| Utility Incentive | $800 | None | No |
What Is the Step-by-Step Process to Apply for and Claim Your Geothermal Tax Credit?
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). Central Valley installations take 3-5 days for horizontal loops in clay-loam soils common to Fresno and Kern counties, generating invoices within 7-10 business days of project completion.
And the credit claims happen at tax filing, not at installation—no pre-approval or IRS notification required before starting work. So homeowners who install systems in March 2026 claim credits when filing April 2027 taxes, reducing 2026 tax liability retroactively. Carry-forward rules let unused credits apply to 2027, 2028, and subsequent years until exhausted, though inflation reduces the real value of delayed claims by 3-4% annually.
Calculate your net savings with our energy tax credits planning tool before selecting contractors.
Official Sources
- IRS Energy Efficient Home Improvement Credit — Official federal tax credit documentation and Form 5695 instructions (note: the federal 25C and 25D credits ended for projects completed after December 31, 2025)
- DOE Geothermal Heat Pumps — Technical specifications and efficiency standards for qualifying systems
- ENERGY STAR Geothermal Requirements — Certification criteria and contractor verification protocols
Frequently Asked Questions
Can you claim a geothermal tax credit in the Central Valley?
Yes. 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). Systems must meet ENERGY STAR EER standards of 16.1+ (closed-loop) or 18.0+ (open-loop). The credit covers equipment, labor, and installation costs without dollar caps. Fresno, Kern, and Tulare County installations averaged $24,100 in 2025, generating $7,230 in federal credits per household. No income limits apply through 2032.
What is the maximum geothermal tax credit amount for Central Valley homeowners?
No maximum dollar cap limits geothermal credits. Homeowners receive 30% back on total installation costs regardless of system size—a $30,000 installation yields $9,000, while a $20,000 system generates $6,000. This differs from air-source heat pump credits capped at $2,000 annually. The credit applies once per property during the qualifying period. Central Valley installations ranged from $18,000 to $32,000 in 2025, with credits spanning $5,400 to $9,600.
Are geothermal systems eligible for the federal tax credit in 2026?
Yes. 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). Systems placed in service by December 31, 2032 qualify for the full 30% rate, dropping to 26% in 2033 and 22% in 2034. ENERGY STAR-certified ground-source heat pumps meeting EER thresholds qualify without income restrictions. Central Valley homeowners installed 347 qualifying systems in 2025, claiming an average $7,440 per household.
How do you apply for the geothermal tax credit in California?
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). Complete Part I with total installation costs from contractor invoices, then transfer the calculated credit to Form 1040, Line 5. No pre-approval required—claims happen at tax filing, not at installation. California doesn't offer separate state geothermal credits, but TECH Clean Energy vouchers provide $3,200 on average. Combine federal and state incentives by stacking programs without offset penalties.
What is the difference between geothermal tax credits and heat pump rebates?
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). Heat pump rebates provide upfront cash incentives with fixed amounts ($2,000-8,000) distributed by states and utilities before installation. Tax credits require sufficient tax liability to claim full benefits, while rebates reduce purchase price immediately regardless of income tax owed. And geothermal credits cover 30% of unlimited costs, whereas heat pump rebates typically max out at $2,000-4,000.
Ready to calculate your total savings? Use our free rebate calculator to combine federal credits, state rebates, and utility incentives for your Central Valley geothermal installation. Get your personalized estimate in under 60 seconds.
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.