Skip to content
Rebate calculator

Mass Save heat pump rebate by system size

Whole-home pays $2,650 per ton in 2026 and $2,350 from January 1, 2027. Either way, the cap is reached at about 3.2 tons.

  • Checked: November 2026

Use the calculator

A bright living room in an older New England home with a slim white wall-mounted heat pump indoor unit above a sofa and snow on the bare trees outside the window

The rebate for each size

Whole-home

TonsInstalled 2026From Jan 1, 2027
1$2,650$2,350
1.5$3,975$3,525
2$5,300$4,700
2.5$6,625$5,875
3$7,950$7,050
3.5$8,500$7,500
4$8,500$7,500
5$8,500$7,500

Partial-home

TonsInstalled 2026From Jan 1, 2027
1$1,125$1,000
1.5$1,688$1,500
2$2,250$2,000
2.5$2,813$2,500
3$3,375$3,000
3.5$3,938$3,500
4$4,500$4,000
5$5,625$5,000

Worked out from Mass Save's published rates: whole-home $2,650 per ton up to $8,500 (2026) and $2,350 up to $7,500 (2027); partial-home $1,125 up to $8,500 (2026) and $1,000 up to $7,500 (2027). Mass Save, Air Source Heat Pumps, checked November 2026. Basic rebates ($250 per ton, up to $2,500 in 2026) apply when you are not replacing fossil or electric resistance heat. Mass Save had no 2027 basic rate published.

Two bar charts comparing Mass Save heat pump rebates for installs in 2026 and installs from January 1, 2027, for 1 to 5 tons. Whole-home falls from $2,650 to $2,350 per ton and the cap from $8,500 to $7,500, so a 3-ton system loses $900 and a 4-ton system loses $1,000. Partial-home falls from $1,125 to $1,000 per ton.

Swipe to see the whole chart.

Mass Save's published per-ton rates and caps, checked November 2026.

Tons, not square feet

Mass Save counts tons: the outdoor unit's AHRI cooling capacity divided by 12,000 BTU. A mini-split rated 36,000 BTU is 3 tons. The tonnage that suits your house comes from a heating-load calculation, which depends on insulation, windows, how the house is laid out and how cold the design day is. Floor area alone does not decide it, and we do not guess tons from square feet.

Ask each installer for the load calculation. For a partial-home job, Mass Save pays a $500 sizing bonus when the equipment meets 90 to 120% of the heating load (ACCA Manual J), and wants a copy of the calculation with the application.

Where the cap bites

  • 2026 whole-home: the $8,500 cap arrives at 3.2 tons. Everything above that is unrebated.
  • 2027 whole-home: the $7,500 cap arrives at 3.2 tons. A 3.5-ton house loses $1,000 against 2026.
  • Small systems: a 2-ton system loses $600 between years. A 3-ton system loses $900.

What is left to pay

Mass Save's own example uses an average whole-home installation cost of $22,000, from its program data on installs completed in 2022. At the 2026 cap that leaves $13,500. At the 2027 cap it leaves $14,500. The cost of your own job is whatever your quote says. We do not publish a price range of our own.

Turn the BTU on your quote into a rebate

Quotes and AHRI certificates list capacity in BTU per hour, not tons. Add up the outdoor units and you have the number Mass Save pays on.

Rebate from the BTU on your quote

Mass Save counts tons as each outdoor unit's AHRI cooling capacity divided by 12,000 BTU. Your quote or the AHRI certificate lists that capacity. Type it in for each outdoor unit.

Your system in tons

3.0 tons

Whole-home Mass Save rebate by rated capacity
AHRI cooling capacityTonsInstalled 2026From Jan 1, 2027
12,000 BTU/hr1$2,650$2,350
18,000 BTU/hr1.5$3,975$3,525
24,000 BTU/hr2$5,300$4,700
30,000 BTU/hr2.5$6,625$5,875
36,000 BTU/hr3$7,950$7,050
42,000 BTU/hr3.5$8,500$7,500

Whole-home: $2,650 per ton up to $8,500 (2026), $2,350 per ton up to $7,500 (2027). The cap is reached at about 38,500 BTU/hr in 2026 and 38,300 BTU/hr in 2027. Tons rule and rates: Mass Save, Air Source Heat Pumps, checked November 6, 2026. The capacity your house needs comes from a room-by-room heating load calculation (ACCA Manual J), not from square feet alone.

Calculator

Rebate estimator

Your size, your town, your rebate

Any of the 351 Massachusetts cities and towns.

What heats the home now?

We do not turn this into a system size. An installer measures your rooms to do that. We pass the number along with your request.

What will the heat pump do?
3 tons

Heat pumps are sized in tons. A ton is how much heating and cooling the system puts out, not what it weighs. Not sure of yours? Leave it at 3. The installer works out the real size for your home.

Common questions

How many tons is my house?

Mass Save pays by tons of cooling capacity (the unit's AHRI cooling capacity divided by 12,000 BTU), not by square feet. The right size comes from a heating-load calculation for your house, so the same floor area can need different tons. Ask the installer for the load calculation.

What is the most Mass Save pays for a whole-home heat pump?

$8,500 in 2026 and $7,500 for installs on or after January 1, 2027. Both caps are reached at about 3.2 tons, so the 2027 cut hits every system size.

Does a bigger heat pump get a bigger rebate?

Up to the cap. A 4-ton system and a 3.5-ton system both pay $8,500 in 2026. Do not buy extra tons for the rebate: Mass Save's sizing bonus rewards equipment sized to 90 to 120% of the heating load.

Can I add a basic rebate for an addition?

Mass Save says customers adding heat pumps to an unconditioned space can receive the basic rebate in addition to the whole-home or partial-home rebate, with total rebates capped at $8,500 per account.

What is the sizing bonus?

A $500 bonus on partial-home projects when the heat pumps are sized to meet the home's total heating needs, 90 to 120% of the heating load at the outdoor design temperature per ACCA Manual J. A copy of the load calculation goes with the application.

Rebate paperwork is part of what we handle. Mass Save sets the amounts. Call (781) 210-8400 or send two photos. Related: heat pump cost after Mass Save, the 2027 change.

Get a price for your size.

Send two photos and your town. We look at them and get back to you. Or call (781) 210-8400.

Send photos, get a price
Call (781) 210-8400Rebate