Montana drivers can legally tint their windows to 35 percent VLT for the front side windows and no less than 20 percent VLT for the rear side and back windows as of 2026. This means the front windows must allow at least 35 percent of visible light to pass through, while the rear windows can be darker but cannot go below 20 percent. These limits are set by Montana Code Annotated § 61‑6‑621 and are enforced to balance safety, law‑enforcement visibility, and driver comfort.
Legal Tint Limits in Montana
Montana’s tint law distinguishes between front and rear windows. The front driver and passenger windows must meet a minimum of 35 percent light transmission, the same standard applied to the windshield except for the top 5‑inch strip. Rear side windows and the back window may be tinted darker, but they cannot be less than 20 percent VLT. Violation of these standards can result in a citation, a fine of up to $250, and a requirement to remove the illegal tint.
Why the Regulations Matter
Law‑enforcement officers rely on clear visibility to assess driver behavior, detect intoxication, and identify concealed weapons. Excessively dark tint can hinder these safety checks and increase the risk of accidents. Additionally, proper tint levels help reduce glare without compromising the ability of other drivers and emergency responders to see inside the vehicle. The state’s thresholds aim to strike a balance between driver comfort—such as heat reduction—and public safety.
How to Verify Your Tint Compliance
Most auto‑glass shops use a handheld tint meter that measures visible light transmission (VLT) as a percentage. The device is placed against the glass; a reading of 35 percent or higher for front windows confirms compliance. For rear windows, the meter should display at least 20 percent. Keep the receipt and meter reading documentation; it can be useful if you are stopped by police.
Penalties for Non‑Compliant Tint
If an officer determines your tint is illegal, you will receive a traffic citation. The fine ranges from $150 to $250, and you may be required to re‑tint or replace the glass at your expense. Repeated offenses can lead to higher fines and potential points on your driver’s license. In extreme cases, a vehicle may be deemed unsafe and placed out of service until corrected.
Frequently Asked Questions
What if my vehicle has factory‑installed tint?
Factory tint that meets or exceeds the legal VLT percentages is automatically compliant. Verify the manufacturer’s specifications; if they are at or above 35 percent for front windows and 20 percent for rear windows, no additional action is needed.
Can I use aftermarket tint that is darker than the legal limit?
No. Aftermarket tint must conform to the legal VLT percentages. Installing darker tint violates Montana law and will result in a citation if detected.
Does the law apply to commercial vehicles?
Yes. Commercial trucks, vans, and buses must adhere to the same VLT standards for their windows. Some exemptions exist for vehicles used by law‑enforcement or emergency services.
Are there medical exemptions for darker tint?
Montana allows a medical exemption for drivers with specific conditions such as photosensitivity. The driver must obtain a signed physician’s statement and a state‑issued permit, which permits darker tint within the prescribed limits.
How often do tint laws change in Montana?
Tint regulations are updated infrequently, typically only when legislative action occurs. As of 2026, the current limits remain unchanged from the 2022 amendment, but drivers should monitor the Montana Department of Transportation for any future revisions.