Mass Save Heat Pump Rebates for Nantucket Homeowners: The 2026 Guide
If you are weighing a heat pump for your Nantucket home, the rebate is usually the number that decides it. As of 2026, that rebate matters more than ever. The federal heat pump tax credits (Sections 25C and 25D) expired on December 31, 2025, which means Mass Save is now carrying the full weight of heat pump incentives in Massachusetts. There is no federal backstop anymore. The state program is the program.
This post walks through exactly how the money works for a Nantucket home in 2026: the three Mass Save tiers, the instant New England Heat Pump Accelerator rebate that stacks on top, who qualifies, the 0% HEAT Loan, what changed this year, and the paperwork we handle so you do not leave money on the table.
North Winds Mechanical is the first and only Mass Save Heat Pump Leader Network (HPLN) contractor on the island. That distinction matters, and we will explain why near the end.
Why Nantucket plays by slightly different rules
Most rebate guides you will read online are written for the mainland. Nantucket has a few wrinkles, and most of them work in your favor.
First, there is no natural gas on the island. Every year-round home here heats with oil, propane, or electric resistance. That is the exact fuel profile Mass Save wants to displace, so almost every Nantucket home sits squarely in the qualifying lane by default. On the mainland, gas customers have to jump through extra hoops. Here, you usually do not.
Second, your Mass Save sponsor here is National Grid, which delivers your power and administers the rebates on the island. Because Nantucket's grid is constrained and peaks hard in summer, National Grid runs programs here you will not find in every town, including a seasonal reduced electric delivery rate for heat pump customers and the Nantucket-exclusive ConnectedSolutions+ program. We keep your paperwork pointed at National Grid from the start, so nothing stalls because a form went to the wrong administrator.
Third, island housing stock is old. Knob-and-tube wiring, vermiculite insulation, and other pre-weatherization barriers turn up constantly in Nantucket homes, and they can quietly block a rebate if they are not caught early. More on that below.
The three rebate tiers (2026 amounts)
Mass Save rebates scale by system size, measured in tons. One ton equals 12,000 BTU of capacity, so a bigger system earns a bigger rebate, up to a cap. There are three tiers, and which one you land in depends on how much of your home the heat pump covers.
Tier Rebate Cap What it covers Whole-Home $2,650 per ton $8,500 Heat pump is the sole source of heating and cooling for the home Partial-Home $1,125 per ton $8,500 Heat pump covers part of the home alongside an existing system Basic $250 per ton $2,500 New heat pump with no requirement to displace existing heat
A few things worth understanding about each tier.
Whole-Home is the big one, and it is where most of our island projects land. Because the rebate is $2,650 per ton up to $8,500, a system of roughly 3.2 tons or larger hits the full cap, so most whole-home jobs reach it or come close.
The 2026 Whole-home Heat Pump Verification Form spells out exactly what this tier requires, and it is worth knowing before you start:
Sizing. The heat pump must be sized to cover 90 to 120% of your home's total heating load at the outdoor design temperature, across 100% of the conditioned space, per an ACCA Manual J calculation. In plain terms, it has to heat the whole house on the coldest day of the year, on its own.
The old system goes. Your pre-existing heating system has to be removed or disconnected. You can keep a boiler in place only to make domestic hot water (an indirect tank or a combi boiler), with its space heating disabled.
Weatherization, but often without any work. The home has to be sufficiently weatherized, and you can satisfy that any one of three ways: the house was built in 2000 or later, a Home Energy Assessment shows less than $1,000 of recommended weatherization, or weatherization recommended since 2013 has already been completed. Clear any one of those and you need no new weatherization to qualify.
Full-time winter occupancy. The home has to be occupied full time during the winter heating season. This is the one that catches seasonal owners, and on Nantucket it matters. A summer-only house generally will not qualify for the Whole-Home tier, though the Partial-Home or Basic tier may still fit.
Partial-Home is for homes that keep an existing heating system and add heat pumps to part of the house. To qualify, the system needs either integrated controls with a minimum switchover setpoint between the heat pump and the existing system, or it needs to completely offset a heating zone in the home.
Basic carries no requirement to displace anything. It is typically used to add comfort to an unconditioned space, like a garage, a sunroom, or a finished attic. It can stack on top of a Whole-Home or Partial-Home rebate for that separate unconditioned space, with the total capped at $8,500 per account.
The $500 sizing bonus
On top of the Whole-Home and Partial-Home rebates, Mass Save pays a $500 bonus when the system is sized correctly with a Manual J load calculation. We run Manual J on every job, so this one is essentially automatic when you work with us.
Stack the rebate and the sizing bonus and a qualifying whole-home project reaches $9,000 in direct Mass Save incentives, before the Accelerator credit below. The bonus does not apply to the Basic tier.
The instant rebate that stacks on top: the New England Heat Pump Accelerator
Here is where working with us changes the math. A Mass Save rebate is normally paid as a check after the install, but we provide it as instant savings applied to your project up front, so you are not floating the money and waiting on a reimbursement. The New England Heat Pump Accelerator (NEHPA) is a separate, federally funded regional program that puts an incentive directly into the equipment cost at the point of sale, and we provide it instantly as well.
For 2026 it pays $650 per outdoor condenser on qualifying cold-climate air-source heat pumps, up to two condensers per address. The distributor discounts the unit, and we pass that discount straight through to you as an instant credit on your invoice. You do not file anything, and you do not wait for it. It simply comes off the price.
The important part: the Accelerator stacks on top of the Mass Save rebate. They are two separate programs, so a typical whole-home job with two condensers can capture the full Mass Save rebate plus the sizing bonus and another $1,300 in instant Accelerator credit. We handle the distributor side of this for you, which matters because the program is new and not every contractor has it dialed in yet. It is part of how we manage the entire rebate process on your behalf.
The 0% HEAT Loan
The rebate knocks down the price. The HEAT Loan handles the rest.
Mass Save offers 0% interest financing up to $25,000 for qualifying upgrades, with terms up to seven years (84 months), no origination fees, no closing costs, and no prepayment penalty. It covers the balance left after your rebate, and it also covers weatherization and pre-weatherization barrier work.
The rate is always 0%, full stop. A couple of details to keep in mind: the $25,000 is a lifetime cap across all of your energy efficiency upgrades, not a per-project number, and the loan runs through a participating lender that you apply to directly, not through us. We give you a clean, detailed proposal so the lender has what it needs from our side.
To put the 0% in perspective, financing $15,000 on a HELOC at 8.5% would cost you thousands in interest over the life of the loan. The HEAT Loan costs you nothing beyond the principal.
One more National Grid perk: the seasonal heat pump rate
This one is not a rebate, but it keeps paying you every winter. Starting November 1, 2025, National Grid introduced a reduced electric delivery rate for qualified residential heat pump customers, applied to usage from November 1 through April 30, the exact window when your heat pump is doing the most work. If your heat pump was installed through a Mass Save program, you may be enrolled automatically. It is a quiet but real reduction in your running cost, and it is one of the reasons the math on a heat pump looks better here than the sticker price alone suggests.
What changed in 2026 (read this before you compare old quotes)
The program tightened this year. If you are looking at a quote from 2024 or 2025, the numbers have moved.
Caps dropped. The Whole-Home rebate fell from $3,000 per ton (capped at $10,000) to $2,650 per ton (capped at $8,500). That is a $1,500 reduction at the top end.
Federal credits are gone. Both the 25C and 25D tax credits expired at the end of 2025. Equipment installed after December 31, 2025 does not qualify for them.
R-410A refrigerant is out. As of January 1, 2026, heat pumps using R-410A were removed from the Mass Save Heat Pump Qualified Products List and no longer earn rebates. Only systems using next-generation refrigerants like R-32 or R-454B qualify. We break down what the shift from R-410A to A2L refrigerants means for your equipment in a separate post. We only quote qualifying equipment, so this is handled on our end, but if you are comparing an older proposal, check the refrigerant before you sign anything.
Rebates are not increasing. The trend is down, not up. Waiting a year is likely to cost you, not save you.
Who qualifies
For a Nantucket home in 2026, the qualifying checklist looks like this:
You are a residential customer with a National Grid electric account (this covers essentially every year-round island home).
You are replacing or displacing oil, propane, or electric resistance heat.
The equipment is on the Mass Save Heat Pump Qualified Products List and is cold-climate rated.
The system is installed by a Heat Pump Installer Network contractor between January 1 and December 31, 2026.
For the Whole-Home tier, the home must be occupied full time in winter and sufficiently weatherized, which many homes already satisfy by being built in 2000 or later or already weatherized (see the Whole-Home requirements above).
One common trap: replacing an existing heat pump with a new heat pump does not qualify for the Whole-Home or Partial-Home rebate. These rebates are built to move homes off fossil fuel and electric resistance, not to swap one heat pump for another.
The paperwork we handle
This is where the rebate is won or lost. The system is only half the job. The other half is doing the program correctly, on time, with the right forms pointed at the right sponsor. Here is what we manage for you:
Manual J load calculation to size the system to the 90 to 120% of design load the program requires, which also unlocks the $500 sizing bonus. We keep the documentation on file in case Mass Save requests it.
Confirming your fuel type and account put you in the qualifying lane before we ever quote the job.
Specifying only qualifying equipment: cold-climate, on the Qualified Products List, using R-32 or R-454B refrigerant.
The New England Heat Pump Accelerator pass-through, handled on the distributor side so the $650-per-condenser credit lands on your invoice instantly, with no form for you to file.
The 2026 Whole-home Heat Pump Verification Form, including the installer certification we sign as your Network contractor, completed correctly the first time.
Checking whether you even need weatherization first, since homes built in 2000 or later, or already weatherized, usually clear the requirement with no work at all. If yours does need it, we point you to the no-cost Home Energy Assessment and Mass Save's weatherization program and flag barriers like knob-and-tube wiring or vermiculite early, before they stall your rebate.
The rebate application and supporting documents, submitted on schedule. For 2026, equipment must be installed by December 31, 2026, and the paperwork has to be received by February 28, 2027.
A clean, detailed project proposal you can take to a HEAT Loan lender, so the 0% financing moves quickly on your end.
Verification inspections. Mass Save randomly selects some projects for inspection before paying the rebate. We install to a standard that holds up when one of ours gets pulled.
Why the Leader Network designation matters
Any contractor in the Mass Save Heat Pump Installer Network (HPIN) can unlock the rebates. The Heat Pump Leader Network (HPLN) is a much smaller, vetted tier that Mass Save launched in 2025. It started with fewer than 50 companies statewide out of the thousands in the broader network. Earning it required demonstrated expertise across heat pump technologies, high customer satisfaction scores, a real quality-assurance process, and additional specialized training.
North Winds Mechanical is the only HPLN contractor on Nantucket. On an island where a botched install means a return ferry trip for parts and a much longer wait, that standard is not a marketing badge. It is the difference between a system that performs through a February nor'easter and one that does not. You can see what that standard looks like in our 32-head Daikin VRF and whole-building ERV install for the Town of Nantucket's workforce housing on Waitt Drive, and in why Nantucket homeowners choose North Winds in the first place.
The bottom line
Heat pumps make more sense on Nantucket than almost anywhere, and in 2026 the stacked incentives still do most of the heavy lifting on cost: the Mass Save rebate and the Accelerator credit, both applied instantly up front, the 0% HEAT Loan for the balance, and a seasonal rate that keeps paying every winter. But the program is tighter than it was, the federal credits are gone, and the details here run through National Grid with an island twist that most online guides miss.
Bring us the house. We will tell you which tier you land in, what the system costs after every rebate, and what the monthly looks like on the HEAT Loan. No guesswork. See the full rundown of the rebates we handle, browse our HVAC services, or request an estimate and we will start the assessment. Click Here to download a copy of the Whole Home Heat Pump Verification Form if eligible.
We install and service heat pumps across the entire island: Town and Mid-Island, Surfside, Cisco, Madaket, Tom Nevers, Polpis, Wauwinet, Shimmo, Monomoy, and Siasconset (Sconset). Wherever your property sits on Nantucket, the rebate rules are the same and so is our standard of work.
North Winds Mechanical 43 Nobadeer Farm Road, Nantucket, MA 508-825-6297 office@northwindsmechanical.com
Rebate amounts, eligibility rules, and deadlines reflect the 2026 Mass Save program as of this writing and are subject to change. This guide is informational and not a guarantee of eligibility. We will confirm the current terms for your specific project before you commit.
