Massachusetts medical malpractice claims must pass through a tribunal if the case is ultimately going to be successful. This is a prerequisite to any medical malpractice claim in Massachusetts  I found the following on Stoneham, Massachusetts attorney Susan M. Mooney’s web site that does a great job of explaining the tribunal system in the context of Massachusetts medical malpractice:

After suit is filed, Massachusetts’s law requires that a malpractice case be heard by a malpractice tribunal (a panel of three (3) persons; typically a judge, a lawyer and a physician). At the tribunal we must present expert witness support, usually by submitting a written report from the expert, that the case has a reasonable likelihood of success. Thus, it is imperative that a written expert opinion is obtained before filing suit. If the tribunal decides that there may be negligence and therefore a likelihood of success, then your case is allowed to proceed through the Court system to trial without any bond requirement. However, the other option available to the tribunal is a decision that there may have been an “unfortunate medical incident” but that it does not rise to the level of negligence. If the tribunal determines that it is an “unfortunate medical incident” your case will be dismissed and if you wish to prevent a dismissal, a bond must be posted with the Court. (The current bond is $6,000.00 per party that you have named as a defendant in a malpractice case). For example, a case against a doctor and a hospital would require a $12,000.00 bond if the tribunal decision was not favorable to you and nevertheless you wished to proceed with the case in spite of the tribunal’s decision.