Tool
Pick the bedrooms, the type of system and the site conditions to get a planning range, then see what the state credit gives back.
The ranges are typical 2026 installed prices for single-family homes in Barnstable and Plymouth counties. They are meant to set expectations before a site visit, not to replace a written quote from a septic contractor.
Planning range
$25,000 – $45,000
Conventional Title 5 system, 3 bedrooms, typical lot, dry soils.
Massachusetts tax credit
Terms from mass.gov, residential property tax credits. Program terms are set by the agencies and change; confirm with the state or county page linked here.
Financing in Barnstable County
Cape Cod homeowners can apply to AquiFund, the county septic loan program, at 0% to 5% for terms up to 20 years, repaid as a betterment on the property tax bill. From 2023 onward a below-market betterment loan no longer reduces the state credit, so the loan and the credit can be used together.
Financing in Plymouth County
AquiFund is a Barnstable County program and stops at the canal. Ask your board of health whether the town runs a Title V betterment loan, and look at the MassHousing septic repair loan, which lends statewide to eligible owner-occupants.
No septic contractor on Cape Cod publishes prices. Eight local companies were checked in September 2026 and none of them list a figure, so the ranges in this tool are assembled from Massachusetts press reporting, town meeting documents, MassDEP guidance and published homeowner examples, then weighted toward the Cape end of each spread.
A conventional Title 5 replacement for a three-bedroom house runs roughly $25,000 to $45,000 installed here. Statewide surveys put simple jobs at $15,000 to $25,000 and complicated ones past $35,000; Cape and South Shore lots sit in the upper half because of sand, water and access. One documented Cape raised-bed replacement came to about $42,000, and groundwater alone explained the difference. An I/A nitrogen-reducing system starts higher, around $35,000 to $60,000, and Eastham told residents in September 2026 to plan on about $40,000 with a spread from $15,000 to $100,000.
Three variables move a quote more than anything else. The type of system, because an I/A unit adds treatment hardware, a control panel and a yearly service contract. The depth to groundwater, because five feet of separation on a low lot means imported fill, a raised bed and often a pump chamber, which is the $8,000 to $15,000 this tool adds for that condition. And access, because a machine that cannot reach the leaching area turns a two-day dig into a week.
Bedrooms matter less than people expect. Because design flow is 110 gallons a day per bedroom, one more bedroom grows the leaching area rather than the tank, and typically adds about $5,000. A tank swap on its own does not move with bedroom count at all.
Nothing here replaces a site visit. Every replacement begins with a deep-hole test and a percolation test witnessed by the board of health, and the result of that one morning decides which half of the range you land in. For the full picture read the replacement cost guide and the Title 5 guide, then ask for a quote. Program terms are set by the agencies and change; confirm with the state or county page linked here.
Money
Two public programs pay for a large share of most Title 5 upgrades. Which one applies depends on the county the house is in.
Statewide, principal residence
Barnstable County homeowners only
Plymouth County homeowners
Program terms are set by the agencies and change; confirm with the state or county page linked here before you count on a number.
Two houses with the same bedroom count can need very different systems. A deep, sandy lot with low groundwater takes a standard leach field. A lot with groundwater four feet down needs a raised bed, imported fill and often a pump chamber, which is where most of the extra $8,000 to $15,000 goes.
The ranges are installed prices that usually include the soil evaluation, the engineered plan and the Disposal System Construction Permit, because contractors quote those together. Design and soil testing on their own run about $2,500 to $5,000. A Title 5 inspection, tree removal and landscaping repair are separate line items.
For tax years 2023 and later the credit is 60% of qualifying costs on up to $30,000 of expenses, so $18,000 is the ceiling for the household. You claim at most $4,000 in any one year and carry the rest forward for up to 5 years, which means a full $18,000 credit takes about five tax years to realise. The home must be your principal residence.
Yes, if the house is in Barnstable County. Since the 2023 tax change the credit is no longer reduced by the interest subsidy on a below-market betterment loan, so you can finance the job through AquiFund at 0% to 5% over up to 20 years and still claim the full credit. Plymouth County homeowners use town betterment loans or MassHousing instead.
The process
It goes to a single septic company that works in your town and handles your kind of job. It is not sold to a list, and you will not get calls from five companies.
Expect a call, usually within one business day. The contractor asks about the house, the inspection report if you have one, and your timing, then books a visit.
After the visit you receive a written estimate with the scope and the permit plan. There is no fee and no obligation. If it is not a fit, say so and that is the end of it.
One call or form, a written quote after a site visit. Free for homeowners, no obligation.