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 two of those filings closely, side by side. Here is what they show.

The source

One rule that makes this possible

Every private-passenger auto 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.

Three findings

What we found when we read them

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

For the exact same household, we found that the gap between a carrier's most expensive Massachusetts place and its least expensive one runs more than 2.5 times over, at each of the two carriers we've read closely so far. Each carrier sets its own price for every place, and the two don't agree on which places belong where in that ranking. For a single, experienced driver, the two carriers only loosely agree on which places are the most and least expensive. Add a newly licensed driver to the same household, and their rankings of the state's places are essentially unrelated — a place that's affordable at one carrier is not reliably affordable at the other. Move from one town to the next, and your premium moves by a different amount depending on who carries you.

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, with nothing else about it changed, and the typical filed increase runs around 51% at one carrier and around 32% at the other. Town by town, the gap between the two carriers typically runs about 22 points. Either way, the difference is in how each carrier weighs a new driver, not in the driver.

Experience is priced even more differently — the widest gap we found.

Eight more years behind the wheel, with nothing else about the household changed, is worth roughly 2 to 4% to one carrier. To another, it's worth roughly 15 to 17%. That's roughly six times more sensitive at one carrier than the other, for the same eight years — the widest disagreement of the three things we measured. Both are pricing the same driver.

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. Two carriers are read closely enough to set side by side here so far, out of the roughly three dozen writing private-passenger auto in Massachusetts. 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.

Have it all looked at →