Massachusetts has passed a new law banning the use of aftermarket LED headlight bulbs in vehicles

Massachusetts has passed a new law banning the use of aftermarket LED headlight bulbs in vehicles that were not originally equipped with LED lighting systems. This measure isn’t driven by concerns over brightness or safety, but by a technical compliance issue with federal regulations  .

Any LED bulb installed into a headlight assembly that was engineered and certified for halogen bulbs is now illegal in Massachusetts. Factory-installed LED systems remain legal, as they meet certification standards from the manufacturer.

Under federal regulations (49 CFR 571.108), a headlight’s lens, reflector, and bulb must be tested and certified together as a system. Simply swapping a halogen bulb for an LED in an uncertified assembly breaks those rules, even if the light output is acceptable and not blinding  

Many drivers upgraded to LED bulbs believing they enhance nighttime visibility and safety. Yet, the law strictly enforces regulatory compliance, not just performance. As a result, legally compliant upgrades must be part of a certified full assembly—not simply plug-and-play bulb replacements.