The carriers don't agree about you.

Massachusetts requires every private-passenger auto insurer to file example premiums for the same handful of standardized households as part of its rate filing with the Division of Insurance. We've read the major carriers' filings side by side. Here is what they show.

The source

One rule that makes this possible

Every private-passenger auto rate filing submitted to the Massachusetts Division of Insurance has to include premiums for the same set of standardized example households — same drivers’ experience, same cars, same coverage limits, changed one variable at a time.

That single rule is what makes this reading possible without guesswork. Since every carrier answers the same question, whatever differs between their answers is the carrier's own view of risk — not a difference in who applied.

These are the carriers' own filed illustrative households, not anyone's actual price. No real family matches one of these examples exactly. Treat them the way the Division built them: a controlled experiment baked into the filing requirement, not a case study of a real customer.

Four findings

What we found when we read them

Carriers don't agree on what a newly licensed driver costs.

The Division's own examples define this driver by years licensed, not age — specifically, someone one year licensed, driving occasionally. Add that driver to a household in the typical town, with nothing else about it changed, and the filed increase runs anywhere from about 32% to about 118%, depending on the carrier. The same driver can cost several times as much in percentage terms depending on who carries the household. The difference is in how each carrier weighs a new driver, not in the driver. What adding a newly licensed driver means for a household →

Carriers don't agree on what experience is worth, either.

Take a driver from 6 to 14 years licensed, with nothing else about the household changed, and the price comes down by roughly 2% at one carrier and roughly 45% at another. Both figures come from carriers pricing the same driver — the difference is in how each one weighs experience, not in the driver.

Where you live matters more than most people assume — and carriers don't all agree on where.

For the exact same household, the gap between a carrier's most expensive Massachusetts place and its least expensive one runs more than 1.5 times over at the major carriers we've read. Each carrier sets its own price for every place. For a single, experienced driver, the carriers only loosely agree on which places are the most and least expensive. Add a newly licensed driver to that household, and most major carriers mostly agree with each other — but one prices those same places very differently, so a place that's affordable at most carriers isn't reliably affordable at that one. Move from one town to the next, and your premium moves by a different amount depending on who carries you.

A home policy changes the auto price too, by a different amount depending on the carrier.

Carriers that write both auto and home let a home policy earn a credit on the auto side, but not by the same amount. In the filings we’ve read, some take a flat 6% to 15% off the auto premium; others set it coverage part by coverage part, from nothing on some parts to about 35% on one. Some carriers even credit a home policy held with a different carrier. Read side by side, the carriers don't just disagree on what a car and a house cost separately; they disagree on how much holding both is worth.

The carrier that's right for your neighbor may not be right for you. Not because of anything either of you did — because the carriers disagree about which of you is riskier.

A household that looks nearly identical to two different underwriters can get two very different answers back. That's why this has to be worked out at the level of your household, not an industry average. A ranking built once, for everyone, tells you what most people should do. It can't tell you what you should do.

Findings above are read directly from each carrier's own rate filings with the Massachusetts Division of Insurance, against the Division's own standardized example households. They describe how each carrier's filed rate structure behaves, not any real household's price, and are not an offer or estimate for any individual. We read the major carriers' filings closely enough to set them side by side; together they write most of the private-passenger auto insurance in Massachusetts, out of roughly three dozen carriers. More are added as their filings are read.

Want your own household looked at this closely?

We open in January 2027 in Massachusetts. Put your household on the list, and when we open, we'll look at everything you hold, line by line, rather than at an average.

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