No cap outside medical malpractice
For an ordinary personal injury claim, Massachusetts imposes no statutory cap on the contingency fee percentage — the fee is set by private agreement, subject to Supreme Judicial Court rules on reasonableness. 33.3%, or one-third, is a commonly used figure.
Medical malpractice: a genuine four-tier sliding scale
G.L. c. 231, § 60I caps contingency fees in a medical malpractice case on a four-step sliding scale: 40% of the first $150,000 recovered, 33⅓% of the next $150,000, 30% of the next $200,000, and 25% of anything over $500,000. The limits apply the same way whether the recovery comes from a settlement, arbitration, or judgment.
A built-in protection for unpaid medical bills
Massachusetts adds a genuinely distinctive safeguard: if, after the fee and case expenses are deducted, the amount left for the plaintiff would be less than the plaintiff's own unpaid past and future medical expenses included in the recovery, the fee agreement becomes unenforceable — unless the fee is 20% or less, is reduced to 20% or less, or is reduced to whatever level actually lets the plaintiff pay off those medical bills.
What else comes out before you do
Case costs — expenses the attorney typically advances during litigation, like expert witness fees, filing fees, and the cost of gathering medical records — are generally reimbursed from the settlement, on top of whichever fee calculation applies.