Mass Save air source heat pumps rebates
For HVAC contractors filing on behalf of a residential customer.
Mass Save pays a per-ton rebate on qualifying air source heat pumps installed in 2026 by an installer in its Heat Pump Installer Network. Which of the three rebate types applies depends on whether the heat pump becomes the home's sole heating source, supplements an existing system, or replaces neither.
2 open questions on this pathway
The official documents disagree or are silent on the points below. We show them rather than picking a reading, and this is why this pathway is not check-supported.
- Whether the $8,500 cap is per account or per installation. The form states a limit of one whole-home rebate per customer account and a maximum of $8,500. The program page separately says a Basic rebate can be combined with a whole-home or partial-home rebate up to a total of $8,500 per account. Whether a second installation at the same account can draw a further rebate is not stated plainly enough to encode.
- Filing deadline. The program page and the form's eligibility check both say documentation must be RECEIVED BY 28 February 2027. The Terms and Conditions on the same form say applications must be POSTMARKED BY 28 February 2027. Those are different rules and they disagree for anything mailed in the final days. Confirm with the program administrator before relying on either. RebateBench will not guess the more favourable reading.
Rebate amounts
| What | Value in this edition | Source |
|---|---|---|
| Whole-home rebate | $2,650 per ton, up to $8,500 | S2 |
| Partial-home rebate | $1,125 per ton, up to $8,500 | S2 |
| Weatherization bonusRequires a Home Energy Assessment plus recommended weatherization, completed within one year before or six months after installation. | $500, partial-home only | S1, S2 |
| Sizing bonusEquipment sized to 90–120% of the total heating load at the outdoor design temperature, per ACCA Manual J, across 100% of the conditioned space. | $500, partial-home only | S1, S2 |
| How a ton is measuredThe program's own definition. It is a cooling figure, and it is not the same as the model's nominal size or its heating capacity. | AHRI cooling capacity ÷ 12,000 BTU | S1, S2 |
| Ceiling | Rebate may not exceed the total installation cost | S2 |
| Whether the $8,500 cap is per account or per installationThe form states a limit of one whole-home rebate per customer account and a maximum of $8,500. The program page separately says a Basic rebate can be combined with a whole-home or partial-home rebate up to a total of $8,500 per account. Whether a second installation at the same account can draw a further rebate is not stated plainly enough to encode. | Unresolved Unresolved | S1, S2 |
Dates and deadlines
| What | Value in this edition | Source |
|---|---|---|
| Installation window | 1 January 2026 to 31 December 2026, inclusive | S1, S2 |
| Filing deadlineThe program page and the form's eligibility check both say documentation must be RECEIVED BY 28 February 2027. The Terms and Conditions on the same form say applications must be POSTMARKED BY 28 February 2027. Those are different rules and they disagree for anything mailed in the final days. Confirm with the program administrator before relying on either. RebateBench will not guess the more favourable reading. | Unresolved 28 February 2027 — but the rule for meeting it is unresolved | S1, S2 |
| Payment processing | 6–8 weeks after an approved submission | S2 |
| Prior program year | Equipment installed in 2025 had a 28 February 2026 deadline | S1 |
Eligibility
| What | Value in this edition | Source |
|---|---|---|
| Sponsor and fuelConfirm the customer's actual sponsor from the bill. A ZIP code does not establish service territory. | Residential customer replacing oil, propane or electric resistance where Cape Light Compact, Eversource, National Grid or Unitil is the electric sponsor; or replacing natural gas where Berkshire Gas, Eversource, Liberty, National Grid or Unitil is the gas sponsor. | S1, S2 |
| Equipment | New, on the Mass Save Heat Pump Qualified Product List, meeting ENERGY STAR Cold Climate. | S1, S2 |
| Installer | Must participate in the Heat Pump Installer Network. The rebate form captures an HPIN Company ID. | S1, S2 |
| Property | Existing account holders only. Not new construction and not major renovation. Whole-home and partial-home require full-time occupancy during the winter heating season. | S2 |
| Whole-home: weatherizationMulti-family buildings of five or more units are exempt from the requirement. Supporting documentation is required only upon request. | Satisfy any one of: (A) home built during or after 2000; (B) Home Energy Assessment recommends under $1,000 of weatherization; (C) weatherization recommendations made during or after 2013 have been completed. | S1, S2, S3 |
| Whole-home: existing system | The pre-existing heating system must be removed, or disconnected from the panel, or its thermostats disconnected, or its fuel line capped. If it stays in place it may serve only domestic hot water, with space heating disabled. | S3 |
| Whole-home: sizing | Sized to 90–120% of the total heating load at the outdoor design temperature, per ACCA Manual J, across 100% of the conditioned space. | S3 |
| Partial-home: integrated control | An integrated control from the Integrated Control Qualified Product List is required for any zone where propane, oil or gas remains in use, set at or below the maximum switchover temperature. Without one, the existing heating must be removed or disabled from the area the heat pumps serve, and that noted on the invoice. | S1, S2 |
| Existing heat pumps | Replacing an existing heat pump with a new one does not qualify for whole-home or partial-home. It may qualify for the Basic rebate. | S1 |
| Combining incentivesRebateBench does not total incentives across programs whose combination it has not verified. | Not combinable with another utility or efficiency-provider offer for the same equipment, except the HEAT Loan. Non-Mass Save incentives may still be used. | S2 |
| Inspection | The sponsor may conduct a post-installation field inspection before payment. Projects are selected at random, and refusing one can forfeit the rebate. | S1, S2, S3 |
Document checklist
| Document | What it must show | Source |
|---|---|---|
| Completed and signed rebate form | MASG-0078, signed and dated by the customer. | S2 |
| Installer invoice | From an HPIN installer, showing installer name and address, outdoor and indoor model numbers, integrated control model numbers where applicable, installation date, installation address, and total install cost per system. | S2 |
| Proof of payment | Accompanying the invoice. | S2 |
| Manual J load calculation | Required with the application for the partial-home sizing bonus. For whole-home, Manual J and/or Manual D is required only upon request. | S2, S3 |
| Whole-home Heat Pump Verification Form | Whole-home only. Signed by BOTH the customer and the HPIN installer — two signatures, not one. | S3 |
Equipment evidence
The form captures the AHRI Certified Reference number, the AHRI cooling capacity in BTU, the resulting number of tons, the install date, and the area served. Integrated control entries capture model, switchover temperature, count and location. A model number typed from memory is not evidence; the AHRI reference and the nameplate are what settle the combination.
Installer requirement
Installation must be completed by a contractor participating in the Mass Save Heat Pump Installer Network. The customer's rebate depends on it, and the whole-home verification form requires the installer's own signature and certification.
Where the application goes
File online at MassSave.com/Savings, or mail to Mass Save Residential Heating and Cooling Program, 1337 Massachusetts Ave, PO Box #228, Arlington, MA 02476. RebateBench does not submit on the contractor's behalf.
Sources
Every fact above cites one of these by id. Each was retrieved and hashed on the date shown; we link the official document rather than restating it.
| Id | Document | Retrieved | SHA-256 |
|---|---|---|---|
| S1 | Mass Save air source heat pumps program page | 2026-09-07 | ecdcddbaefed921f… |
| S2 | Residential Air Source Heat Pump Rebate Form (MASG-0078)Revision 0078_ASHP_12.25 | 2026-09-07 | 872d1743c1810f1a… |
| S3 | 2026 Whole-home Heat Pump Verification FormRevision 0078_WHV_12.25 | 2026-09-07 | 053d011fe6d005f9… |
Administered by
The Sponsors of Mass Save (Berkshire Gas, Cape Light Compact, Eversource, Liberty, National Grid, Unitil)
Where it applies
Massachusetts. Customers of Berkshire Gas, Cape Light Compact, Eversource, Liberty, National Grid, Unitil.
Confirm the customer's actual sponsor. A ZIP code does not establish service territory.
Official source
Mass Save official program page
Last confirmed to resolve 2026-09-07. The program administrator decides eligibility and payment.
Read the requirements and checklist
RebateBench is in private pilot and no pathway is packet supported yet. If this is a program you file, we would like to verify it with you.
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