Efficiency Maine changed how insulation rebates work on October 1. The rebate used to be a percentage of what you spent. Now it is a flat amount for each area of your home you insulate, with air sealing paying a separate rebate on top. That is easier to understand, but it also means the old rules of thumb no longer apply. The only way to know what a rebate is worth is to run real numbers.
Below are six examples, calculated with the same rules as Mattra’s rebate calculator. If you want the full explanation of what changed, start with what changed on October 1. If you just want to see what your own house might get, skip to the examples.
How the rebate is calculated now
Four things set your number:
- The area. Attic, wall, and basement (or a mobile home underbelly) each count as their own area, and each earns its own rebate.
- How much space you insulate in that area. At least 250 square feet earns the smaller amount, and at least 500 square feet earns the larger amount. An area under 250 square feet earns nothing.
- Your income tier. Any income, moderate income (adjusted gross income up to $70,000 for individual filers or $100,000 for joint filers), or low income (MaineCare, HEAP, SNAP, or TANF).
- Air sealing. It now earns its own rebate: $150, $225, or $300 for the attic, $100, $150, or $200 for a basement or underbelly, and $50, $75, or $100 for the living space, depending on your tier.
Each area pays $1,000, $1,500, or $2,000 for 250 to 499 square feet, and $2,000, $3,000, or $4,000 for 500 or more, for any, moderate, and low income. Everything adds up to a lifetime limit of $8,600 per home, or $5,600 per mobile home.
Six homes, six rebates
| Home | What gets done | Tier | Rebate |
|---|---|---|---|
| 1. Ranch in Auburn | Large attic (500+ sq ft) plus attic air sealing | Any income | $2,150 |
| 2. Same house, different household | Same work | Low income | $4,300 |
| 3. Small cape | 400 sq ft attic plus air sealing | Any income | $1,150 |
| 4. Whole-home project | Attic, walls, and basement, plus attic and basement air sealing | Moderate income | $8,600 (capped) |
| 5. Mobile home | Underbelly (500+ sq ft) plus underbelly air sealing | Low income | $5,200 |
| 6. Mobile home, any income | Same work | Any income | $3,100 |
Homes 1 and 2: the same attic, two very different rebates
A large attic at any income earns $2,000 for the insulation and $150 for sealing the attic, which is $2,150. The same work for a low-income household earns $4,000 and $300, which is $4,300. The work is identical, so your tier matters as much as the project does. That is why it is worth checking whether you qualify for the income-based rebates, because the verification takes just a few minutes.
Home 3: a small attic still counts
A 400 square foot attic is in the smaller band, so it earns $1,000 plus $150 for air sealing. Nothing below 250 square feet qualifies, so it is worth measuring rather than guessing.
Home 4: why a whole-home job hits the cap
At moderate income, each of three areas pays $3,000, which is $9,000, and the two air sealing rebates add $375. That is $9,375, but the program stops at $8,600. This is the real maximum, and it is the number to plan around. A whole-home project is where the new rules pay the most, because every area counts on its own.
Homes 5 and 6: mobile homes
A mobile home underbelly earns more than a standard area: $3,000, $4,000, or $5,000 by tier. Add underbelly air sealing and you reach $3,100, $4,150, or $5,200. The lifetime limit for a mobile home is $5,600, so an underbelly job comes close to the whole allowance. Two rules to know: a mobile home can claim a basement or an underbelly rebate, but not both, and mobile home walls and skirting insulation are not covered.
Four things that can shrink your rebate
- You already have a lot of insulation. The rebate only covers space whose existing insulation is at or below a limit: R-21 for an attic, R-5 for a wall or basement, and R-11 for a mobile home underbelly. A well-insulated attic at R-30 earns no insulation rebate at all, although air sealing is a separate rebate. This catches many homeowners off guard, and it is why we measure first.
- You have already used some of your lifetime limit. Rebates you received before, including under the old percentage program, count toward the $8,600. A home that collected $4,000 in the past has $4,600 left.
- The area is too small. Under 250 square feet in an area earns nothing for that area.
- The rebate cannot exceed the cost of the work. On a very small job, the rebate is limited to what the job actually costs.
What you actually have to do
- Get your home measured. The eligibility rules depend on what is already in your attic, walls, and basement, so this comes first. Mattra does it at a free assessment.
- If you are income-eligible, verify first. Low- and moderate-income households must be verified by Efficiency Maine before the work, and the home has to be your principal residence. Mattra submits the reservation request on the low- and moderate-income jobs.
- Hire a Residential Registered Vendor. Efficiency Maine only pays when the work is done by one. Mattra is one.
- Expect testing. Efficiency Maine requires blower door tests before and after the work in most cases, and the finished job has to meet its Weatherization Requirements Checklist, including R-49 for a blown-in attic.
- File the claim within six months. Efficiency Maine asks you to allow about six weeks to process it. Mattra prepares and submits the paperwork, and low-income rebates are paid to the contractor, so they show up as a discount on your bill.
What if the rebate does not cover the whole cost?
It usually will not, and that is normal. The rebate lowers the cost, and the Efficiency Maine Green Bank can finance the rest, with loans from 0% APR and no lien on your home. You do not need a rebate to qualify for a loan, and the loan has to be in place before the work starts. See every loan term and requirement.
If your project finished before October 1
The new amounts apply to work completed on or after October 1, 2026. Work finished before that date is still paid under the old percentage rules, and you have six months from completion to file the claim. If you finished a project in September and have not claimed yet, do not let it sit.
Find out what your home would get
These six homes are examples, not quotes. Your own number depends on what is in your attic, how big each area is, and which tier you qualify for. Try the rebate calculator for a quick estimate, or book a free assessment and we will measure your home and tell you exactly which areas qualify before any work begins.
See how the Efficiency Maine rebate works, or schedule a free assessment.