Massachusetts insurance companies are under strict statutory mandates to handle your personal injury claim "reasonably." The primary statute which governs the conduct of Massachusetts insurance companies, and their handling of Massachusetts personal injury claims, is M.G.L. c. 176D.
Whether you have a claim stemming from a Massachusetts motor vehicle accident, slip and fall, dog bite, homeowners claim, whatever, Massachusetts insurance companies must treat your claim fairly and reasonably. This does not mean they have to pay each and every claim. What it means is that if you have a valid Massachusetts personal injury claim and the insurance company either arbitrarily denies it, or offers an unreasonably amount of money to settle the claim, you may have a valid claim for "unfair and deceptive acts or practices" against that insurance company.
If it is found that the Massachusetts insurance company violated M.G.L. 176D, that in turn is a violation of M.G.L. c.93A, which potentially subject the insurance company to multiple damages. I must stress that if you are handling your Massachusetts injury claim on your own, and you feel that the relevant insurance company has treated your claim unreasonably, I suggest you consult with a Massachusetts personal injury lawyer right away. Successfully bringing a 176D/93A claim against an insurance company is difficult for someone not trained in Massachusetts personal injury law.