The clock
Massachusetts runs a comp claim on two clocks, not one
The first is notice to your employer — as soon as practicable; there is no rigid statutory deadline. No number is named, which is not the same as no deadline — the longer the gap, the easier it is for the insurer to argue the delay cost it the chance to investigate. The second is the claim itself, filed with the state: four years from the point you knew, or should have known, the injury was work-related. That is longer than the 3 years an ordinary MA injury lawsuit gets — but it is the notice clock above, not this one, that decides most claims. A workplace injury commonly takes 9 to 18 months to reach maximum medical improvement, which is when the permanent-impairment part of the claim can finally be rated. That sits comfortably inside the 48-month filing window, so the pressure here is on the notice deadline rather than this one. And if someone other than your employer contributed to it — a subcontractor, a defective machine, a driver — that separate liability claim runs on Massachusetts's general 3-year injury deadline instead. Two clocks on the same accident, and only one of them is the comp one.
Typical time to settle9–18 months
Deadline to file suit48 months