Massachusetts’s inspection program requires at least 35% light transmission through the finished glass-and-film installation on ordinary side and rear windows. Its current guidance, statute and January 2025 inspection regulation were checked; their different wording is explained below.
Read the official sources ↓Rules by window
| Window | Requirement |
|---|---|
| Windshield | Transparent top strip only. Keep it within the uppermost six inches, above the AS-1 boundary and out of the driver’s direct forward view; do not treat six inches as permission to cross a higher AS-1 mark. |
| Front side | At least 35% combined glass-and-film transmission under the state inspection program’s published meter test. The statute also contains a 35% reflectance provision and a two-outside-mirror condition. |
| Rear side | At least 35% combined transmission for ordinary aftermarket tint. Factory-compliant glazing and rear windows on qualifying public-livery vehicles other than taxicabs have separate exceptions; an SUV label alone does not exempt later-applied film. |
| Rear window | At least 35% combined transmission for ordinary aftermarket tint, with two outside rearview mirrors. The factory-glazing and qualifying public-livery exceptions also apply. |
How the inspection sources fit together
The state’s Mass Vehicle Check program currently links an Aftermarket Window Tint Guidelines PDF that expressly rejects a meter reading below 35% and says the reading includes both the window and the film. This establishes the published inspection threshold; low reflectance alone should not be treated as permission for arbitrarily dark film.
General Laws chapter 90, §9D(4) uses “or” between no more than 35% reflectance and at least 35% transmission. The January 3, 2025 version of 540 CMR 4.04(8)(g) instead refers to the federal safety-glass standard and does not state a 35% figure. The published 35% meter test comes from the inspection program’s guideline. These documents have different wording, so the inspection guidance should be read alongside the law and regulation.
The regulation requires both outside rearview mirrors when rear glass has aftermarket tint and prohibits advertising or vehicle-wrap material on windows. It separately exempts federally compliant factory glazing, out-of-state registrations and specified medical, livery and official-use vehicles.
Medical waiver
Apply to RMV Medical Affairs with the original application and certification by a Massachusetts-licensed medical doctor. The current form considers permanent conditions only and requires the clinical diagnosis behind photosensitivity or photophobia. Eligibility is limited to a qualifying private passenger vehicle owned or operated by the person with the certified condition; RMV approval is required.
The waiver covers side and rear windows, not windshield tint below the permitted AS-1/top strip. RMV says waivers issued after January 16, 2025 arrive with an updated registration; keep both in the vehicle.
Before you rely on this guide
This is general information, not legal advice, a vehicle inspection, or permission to install a particular film. Exceptions and enforcement procedures can depend on your circumstances.
- Research checked October 14, 2026. The 35% meter test is attributed to the inspection program’s currently linked guidance, whose filename dates to 2017; the regulation compilation is dated January 3, 2025.
- The statute uses “or,” while the regulation refers to the federal safety-glass standard. Those are different statements, and neither this summary nor a film label guarantees that a particular installation will pass inspection.
- No authoritative statewide film-color or ordinary consumer label requirement was verified.
The research date shows when the sources were checked. It is not the date the law took effect, and it does not mean this page is monitored continuously. This research preview still awaits human editorial review; we do not claim attorney review.
Official sources
- Massachusetts General Laws chapter 90 §9D ↗
Current official statute; exact reflectance/transmission wording, windshield strip, mirrors and exceptions.
- Mass Vehicle Check aftermarket tint inspection guideline ↗
Currently linked by the state inspection program’s Station & Inspector Resources page; explicitly rejects readings below 35% through both film and glass. Filename is dated 2017, not a new 2026 rule.
- Mass Vehicle Check station and inspector resources ↗
Current program page directly links the tint guideline; Massachusetts Vehicle Check is the joint RMV/MassDEP inspection program.
- 540 CMR 4.00, January 3, 2025 compilation ↗
Full 39-page PDF retrieved directly from Mass.gov; metadata identifies Massachusetts Register #1538, January 3, 2025. Section 4.04(8)(g) retains the federal-standard wording.
- RMV tinted glass waiver ↗
Medical process, windshield exclusion and updated registration handling.
- RMV Application for Tinted Glass Waiver ↗
Current posted form MAB121_0825, retrieved in full; permanent-condition/physician requirements, side/rear-only waiver and windshield exclusion.