Window tint laws in Montana (2026)

The rules, window by window

Windshield

Sunscreening material below the AS-1 line must be clear and transparent; sunscreening material above the AS-1 line may not be red, yellow, or amber in color.

The standard in the law's own words

Beyond the numeric transmission and reflectance figures, the statute's windshield provision is phrased qualitatively for the area below the AS-1 line, requiring it to remain 'clear and transparent' rather than setting a percentage.

Reflectivity

Sunscreening or other transparent material on front side windows, and on the rear window or side windows behind the front seat, may not have a luminous reflectance of more than 35% (Mont. Code Ann. section 61-9-405(4)(b)-(c)).

Color restrictions

Sunscreening material above the windshield AS-1 line may not be red, yellow, or amber in color (Mont. Code Ann. section 61-9-405(4)(a)).

Medical exemption

The Montana Highway Patrol or a local law enforcement agency may grant a waiver of the sunscreening standards for medical reasons, based on an affidavit signed by a licensed physician, licensed physician assistant, or advanced practice registered nurse, or for safety or security reasons.

Enforcement

A person who owns or operates a motor vehicle in violation of the sunscreening standards, or who applies sunscreening material resulting in a violation, commits a misdemeanor punishable under Mont. Code Ann. section 46-18-212.

Notes

The 14% light-transmission floor for the rear window and side windows behind the front seat, and the 35% reflectance ceiling that applies to both zones, do not apply to the rear window or side windows behind the front seat on a multipurpose vehicle, van, or bus, per Mont. Code Ann. section 61-9-405(4)(c); those vehicle types are effectively unrestricted in the rear zone. The statute also exempts multipurpose vehicles with manufacturer-installed tinted glass, hearses, ambulances, government vehicles, and vehicles operating under a granted waiver (section 61-9-405(7)). The fetched text did not specify whether transmission/reflectance is measured as net film alone or combined glass-plus-film; this is left unconfirmed rather than guessed. Passenger-car (non-MPV) numbers are used in the numeric fields above.