Missouri window tint laws require the front side windows to let through at least 35% of visible light, give or take three percentage points, and prohibit aftermarket tint film on the windshield except for a strip along the top that mirrors the factory-tinted area. Rear side windows and the back glass have no darkness limit. The rules live in RSMo 307.173, and breaking them is a Class C misdemeanor carrying fines up to $750.
Front Side Windows
The two windows immediately to the left and right of the driver, along with any front sidewing vents, must allow at least 35% visible light transmission (VLT). The statute builds in a tolerance of plus or minus three percentage points, so a meter reading of 32% is still within the law. Reflectance is capped at 35% as well, again with a three-point tolerance, which keeps the glass from bouncing sunlight or headlights back at other drivers.1Missouri Revisor of Statutes. Missouri Code 307.173 – Specifications for Sun-Screening Device Applied to Windshield or Windows
At 35% VLT, roughly a third of available light gets through. Going darker than that on the front sides without a medical permit is where drivers run into trouble.
Windshield
Aftermarket tint film on the windshield itself is not allowed. What you can have is the factory-tinted glass that comes with many vehicles (or an equivalent replacement), plus tint material along the upper portion of the windshield in the area manufacturers normally tint during production. The statute does not use the term “AS-1 line,” but that factory strip at the top is the practical boundary.1Missouri Revisor of Statutes. Missouri Code 307.173 – Specifications for Sun-Screening Device Applied to Windshield or Windows
Labels, stickers, and informational signs are permitted on the windshield and other windows as long as they do not interfere with the driver’s forward view. Recreational vehicles, as defined by Missouri law, may apply tinted or solar screening material without the same restrictions, provided the driver’s normal line of sight is not blocked.
Rear Side Windows and Back Glass
The prohibition in the statute reaches only the windshield, the front sidewing vents, and the windows immediately to the left and right of the driver. The rear side windows and the back windshield are not on that list, so they are not held to the 35% VLT standard.1Missouri Revisor of Statutes. Missouri Code 307.173 – Specifications for Sun-Screening Device Applied to Windshield or Windows
This applies the same way to sedans, SUVs, and minivans. The statute does not distinguish between vehicle body types. What always has to meet 35% VLT are the two front side windows.
Medical Exemption for Darker Front Tint
If a medical condition requires extra protection from sunlight, you can apply for a permit that authorizes darker tint on the front side windows. You need a physician’s prescription issued within the past year that identifies the serious medical condition and states the specific tint percentage you need. Conditions like lupus, albinism, and severe photosensitivity are common reasons drivers pursue these permits.2Secretary of State. 11 CSR 30-7.010 – Motor Vehicle Window Tinting Permits
Take the prescription and the vehicle to your local Missouri State Highway Patrol headquarters, where the Motor Vehicle Inspection Division handles the application. One prescription covers multiple vehicles, but each vehicle must be brought in for inspection. A certifying officer verifies the prescription, issues the permit, and places a sticker on the inside lower-left corner of the windshield along with a decal on the rear glass or rear bumper. You keep a copy of the permit in the vehicle at all times.2Secretary of State. 11 CSR 30-7.010 – Motor Vehicle Window Tinting Permits
The permit lasts as long as you own the vehicle. Sell the car and buy another, and you start the process over. A lost or damaged permit is replaced the same way.2Secretary of State. 11 CSR 30-7.010 – Motor Vehicle Window Tinting Permits
Historical Plates
Vehicles registered with historical license plates are exempt from Missouri’s tint rules entirely. Neither the 35% VLT standard nor the windshield restrictions apply.1Missouri Revisor of Statutes. Missouri Code 307.173 – Specifications for Sun-Screening Device Applied to Windshield or Windows
Penalties
Non-compliant tint is a Class C misdemeanor. The maximum fine is $750, and the offense carries up to 15 days in jail, though jail time for tint alone is unusual.1Missouri Revisor of Statutes. Missouri Code 307.173 – Specifications for Sun-Screening Device Applied to Windshield or Windows3Missouri Revisor of Statutes. Missouri Code 558.002 – Authorized Fines
Officers check compliance with handheld tint meters that read VLT directly off the glass. A reading below the legal threshold gets you a citation, and repeat stops with the same film can bring repeat fines.
Safety Inspection Failures
Illegal tint will also fail your vehicle at Missouri’s safety inspection. The statute says a vehicle in violation of the tint rules cannot be approved during any inspection conducted under sections 307.350 through 307.390. Because a passing safety inspection is tied to registration renewal, non-compliant film can keep you from legally driving the vehicle until it is removed or replaced.4Missouri Revisor of Statutes. Missouri Code 307.173 – Specifications for Vision-Reducing Material Applied to Windshield or Windows
Most drivers get caught here rather than at a traffic stop. Handling the tint before the inspection is due saves a failed test and a return trip.