The 30% Credit Ended on December 31. The Ground Under Your Lawn Didn't Change: What a Geothermal Heat Pump Really Costs in Potomac, Great Falls, Bethesda & McLean (2026)
For most of the last decade, the geothermal pitch in Potomac and Great Falls went like this: yes, it costs a lot more than a conventional system, but the federal government pays 30% of it, with no cap. That sentence is no longer true.
The federal Residential Clean Energy Credit (Section 25D), which covered geothermal heat pumps at 30%, was terminated by the 2025 budget law (Public Law 119-21, commonly called the One Big Beautiful Bill) for expenditures made after December 31, 2025. The IRS’s guidance on the change says an expenditure is treated as made when installation is completed, so a system contracted in late 2025 but finished in 2026 does not qualify.
What hasn’t changed is the physics, the lots, and the kind of house where geothermal still earns its place. Here’s what the geothermal heat pump cost in Potomac, MD and the surrounding DMV looks like in 2026, what the well permits involve, and how to decide whether it’s still right for you.
First, Clear Up the Credit Confusion
You will still find contractor pages and older articles saying the geothermal credit “runs through 2032.” That was the Inflation Reduction Act schedule, and it was replaced. As of fall 2026:
- Federal 25D credit for geothermal: gone for installations completed after December 31, 2025. If you finished a system in 2025 and couldn’t use the whole credit, ask a tax professional about carrying the unused amount forward.
- Maryland’s Geothermal Rebate Program: closed. The Maryland Energy Administration offered $3,000 for a new ground-source system, but designated FY26 (which ended June 30, 2026) as the program’s final year, and its application portal closed to new applications after requests exceeded the budget. Don’t count on it unless MEA announces a successor.
- Maryland geothermal RECs (GRECs): Maryland’s renewable portfolio standard includes a carve-out for geothermal heating and cooling. According to the Maryland Public Service Commission, residential systems installed on or after January 1, 2023 that meet ENERGY STAR and pass final inspection can generate credits that may be sold. Values move with the market; treat them as a modest offset, not a financing plan.
- Virginia and utility programs: we found no statewide Virginia rebate aimed at residential geothermal. Utility programs (EmPOWER Maryland, Dominion) and the income-qualified federal state rebates change often; confirm with your utility, MEA or Virginia Energy.
- Third-party ownership: the commercial investment credit for geothermal heat pump property (Section 48) survived the law. That lets a company own a residential system, claim the credit itself, and lease the system to the homeowner. A few providers now offer monthly-payment models. Read those contracts like a solar lease: term, escalators, maintenance, and what happens when you sell.
A system that used to net out at 70% of its price now costs full price if you buy it outright, so the decision is a design and lifestyle question again.
Geothermal Heat Pump Cost in Potomac MD: Planning Ranges
Every geothermal quote has two halves: the equipment inside the house and the loop field outside. The loop is where the DMV’s big lots and rocky Piedmont ground drive the price.
Larger Potomac, Great Falls and McLean homes often need five to eight tons of capacity or more, split across zones or multiple units, and the drilling scales with capacity. For planning in our market, homeowners should roughly expect:
| Scope | Rough planning range |
|---|---|
| Moderate home, single system, vertical wells, existing ducts reusable | Often in the $35,000–$60,000 range |
| Large home, multiple units or zones, vertical well field | Commonly $60,000–$120,000+ |
| Add-ons: desuperheater for domestic hot water, hydronic floors, duct replacement, electrical service work | Priced separately; can add materially |
These are planning estimates, not quotes. The biggest swing factors:
- Drilling conditions. Vertical boreholes are commonly drilled a few hundred feet deep. Rock, groundwater and access for the rig affect cost more than anything inside the house.
- Ductwork. Geothermal delivers steady, moderate-temperature air; undersized or leaky older ducts may need redesign.
- Electrical capacity. An all-electric conversion can push an older 150- or 200-amp service. See our 200-amp service upgrade guide.
- Landscape restoration. Budget for lawn, irrigation and hardscape repair around the well field.
Where Geothermal Still Makes Sense Without the Credit
Without a subsidy, geothermal has to win on merit. It still does in specific situations.
You’re replacing oil, propane or failing resistance heat
Potomac and Great Falls homes beyond gas mains often heat with oil or propane, the fuel bills geothermal displaces most dramatically. If you’re paying several thousand dollars a year for delivered fuel, the operating-cost gap can matter even at full price.
You’re building new or doing a gut renovation
When the yard is already torn up for an addition, a pool or a new foundation, the marginal cost of drilling falls, and ducts can be designed for the system from scratch. Montgomery County’s Bill 13-22 directs the county to adopt all-electric standards for most new construction by the end of 2026 (a federal court rejected a challenge in March 2026); confirm current requirements with the Department of Permitting Services. Ground-source is a natural all-electric option. Plan the loop field during site design, before the house footprint, septic field and driveway are fixed.
You plan to stay 15+ years
Buried loops are generally expected to last decades, and indoor equipment isn’t exposed to weather. The longer you stay, the more of that durability you collect.
There is also no outdoor condenser, a real benefit where the side yard is a pool terrace or formal garden.
When Air-Source Is the Better Answer
For many Bethesda and Chevy Chase homes on smaller lots with gas service, a high-efficiency cold-climate air-source heat pump, sometimes paired with an existing furnace as backup, will deliver most of the comfort for a fraction of the installed cost. If your lot doesn’t have room for a drill rig, or wells can’t meet setbacks from the house, septic, utilities and property lines, the decision is made for you.
A fair comparison prices both systems with the same duct and electrical scope and compares 15-year cost of ownership. If you have a boiler and radiators rather than ducts, read our boiler replacement guide first; the options are different. For the envelope side of the same decision, see energy upgrades after the credits ended.
Geothermal Well Permits: The Loop Field Is Regulated Like a Well
Montgomery County, MD (Potomac, Bethesda, Chevy Chase)
Montgomery County’s Department of Permitting Services (DPS) says a well permit must be obtained before drilling a well for any purpose, geothermal systems included. The licensed well driller submits the state drilling permit application to DPS, must notify the county one business day before drilling, and must request an inspection before grouting the well. Permits are valid for twelve months and can be extended in six-month increments.
The county’s geothermal well guideline (dated September 2022) requires closed-loop vertical wells and lists minimum setbacks, including roughly:
- 50 feet from a septic tank, drainfield or septic reserve area
- 50 feet from stormwater management devices
- 30 feet from drinking-water and irrigation wells
- 15 feet from roads and public rights-of-way
- 10 feet from building foundations, underground utilities, property lines and easements
On Potomac lots with septic systems and a drinking-water well, those distances can decide where the field goes, or whether it fits. Setback figures change; confirm the current guideline with DPS before design. Expect mechanical and electrical permits for the equipment as well.
Fairfax County, VA (Great Falls, McLean)
In Fairfax County, a vertical well system needs a well permit from the Fairfax County Health Department, and county guidance says the wells must be installed by a licensed well water supply provider. The county identifies vertical wells as the predominant type installed there. The well permit comes before the mechanical permit, and electrical permits and a site plan are also required. Homeowners may pull permits themselves, but the county strongly recommends a properly licensed contractor act as the responsible party.
Washington, DC
Most rowhouse and small-lot DC properties lack room for a well field; some larger upper Northwest lots have it. Any drilling needs District well approvals plus building permits.
How to Get a Quote You Can Compare
Ask every bidder to specify:
- Load calculation (Manual J or equivalent), not a rule of thumb.
- Loop design: number of boreholes, depth, spacing, and who performs the drilling.
- Duct scope: reuse, modify or replace, with static pressure testing.
- Electrical scope: any panel or service upgrade.
- Permits and restoration: well, mechanical, electrical, and landscape repair.
- Warranty: separate manufacturer and installer terms for loop, indoor equipment and labor.
- Incentives assumed: any quote still showing a 30% federal credit for a 2026 install is out of date.
For the wider permitting picture, see our guide to navigating DMV permits and regulations.
Frequently Asked Questions
Is there still a federal tax credit for geothermal in 2026?
Not for homeowners who buy the system. The Section 25D residential credit ended for expenditures made after December 31, 2025, and the IRS treats an expenditure as made when installation is completed. A company that owns and leases a system may still claim the commercial Section 48 credit.
How much does a geothermal heat pump cost in Potomac, MD?
Costs depend heavily on home size and drilling conditions. As a rough planning estimate, moderate homes often land in the $35,000–$60,000 range, and large Potomac or Great Falls homes with multiple units can exceed $100,000. Get a site-specific load calculation and loop design before relying on any number.
Do I need a permit to drill geothermal wells in Montgomery County?
Yes. Montgomery County DPS requires a well permit before drilling for geothermal systems, and the county’s guideline sets setbacks from septic systems, wells, foundations, utilities, property lines and rights-of-way.
Is geothermal worth it without the tax credit?
It can be when you’re replacing oil or propane, building new, or staying long term. On smaller lots with gas service, cold-climate air-source is often the better value.
Plan the System Around the House and the Lot
Karma Construction Group has built and renovated homes across the DMV since 2012, including custom homes and major renovations where the mechanical system has to be planned alongside the architecture and the site. Whether the answer is geothermal, air-source or a hybrid, we help homeowners weigh the options for their house and their lot. Karma Construction Group is licensed in Maryland (MHIC #108917) and Virginia (Class A Contractor 2705178913).
Call 202-798-7663 or request a free consultation at karmaconstructiongroup.com to plan your heating and cooling before your next renovation or custom build.