California’s window tint medical exemption, authorized under Vehicle Code Section 26708(b)(10), lets drivers install darker-than-standard tint on their front side windows when a licensed physician certifies they have a medical condition requiring protection from direct sunlight.1California Legislative Information. California Vehicle Code 26708 The exemption lives or dies on the paperwork: a signed physician’s letter kept in the vehicle at all times.
What the Exemption Actually Allows
Without an exemption, front side windows in California are nearly transparent by law. Aftermarket film must transmit at least 88 percent of light on its own, and the window as a whole must still let through 70 percent of visible light. That ceiling tracks the federal safety standard for glazing in driving-visibility areas under FMVSS No. 205.2Federal Register. Federal Motor Vehicle Safety Standards; Glazing Materials Rear side windows and the rear window can be any darkness, so the medical exemption only matters for the two front side windows.
The exemption permits sun screening devices on the side windows next to the front seats when the driver or a front-seat passenger has a qualifying condition. It is not a blanket license to install the darkest film on the market. The devices still have to meet the specifications in Vehicle Code Section 26708.2, which governs what qualifies as a sun screening device. A professional installer familiar with California’s rules can match a product to those specs.
One other limit worth knowing: the exemption covers front side windows. The windshield itself is still restricted to non-reflective tint on the top four inches only, even with a physician’s letter.
How to Qualify and Get the Letter
The process starts with your doctor, not the DMV. Make an appointment with a licensed physician or surgeon, explain that you need documentation to support darker window tint, and ask for a signed letter certifying your condition and your need to be shielded from direct sunlight. California law requires the letter to be signed by a licensed physician and surgeon, and the person with the condition must keep it in the vehicle.1California Legislative Information. California Vehicle Code 26708
California does not prescribe a rigid template for the letter. A strong one typically includes:
- Your full legal name
- The specific diagnosis
- A clear statement that the condition requires protection from direct sunlight
- The physician’s signature, printed name, and medical license number
- The date the letter was issued
Specificity matters. A vague note saying the patient needs tinted windows technically satisfies the statute, but it invites questions during a traffic stop or in court. A letter that names the condition and explains why sun exposure is medically harmful leaves little room for dispute.
The statute does not set an expiration date for the letter. A document dated several years ago is still legally valid for a chronic condition, but refreshing it at an annual checkup keeps the paperwork visibly current and avoids ambiguity. Some drivers also file form REG 256A with the DMV to create a formal record, though the statute’s roadside requirement is the physician’s letter in the vehicle.
Once you have the letter, take it to a tint shop and have the installer apply film that complies with Section 26708.2. Doing this before any citation is far cleaner than scrambling for documentation after one.
Which Medical Conditions Qualify
The statute lists no specific diagnoses. It covers any condition for which a physician certifies the person needs to be shielded from direct sunlight. In practice, conditions that commonly support an exemption include:
- Lupus, systemic or discoid, where UV exposure can trigger flares involving skin lesions, joint pain, and organ inflammation
- Xeroderma pigmentosum, a rare genetic disorder that leaves the skin extremely vulnerable to UV damage and dramatically raises skin cancer risk
- Porphyria, a group of disorders where sunlight triggers painful skin reactions
- Severe photosensitivity, whether as a standalone condition or as a side effect of medications such as certain antibiotics, chemotherapy drugs, or immunosuppressants
- A history of melanoma or other high skin cancer risk requiring ongoing UV protection
- Severe light sensitivity from eye conditions such as keratitis, albinism, or post-surgical complications
The physician’s clinical judgment carries the exemption. If your doctor believes sunlight poses a genuine medical risk to you and is willing to document it, the specific diagnosis matters less than the documented need.
Clear UV Film: An Alternative Without a Medical Letter
If your real concern is ultraviolet radiation rather than reducing visible light, California offers a separate path that requires no medical documentation. Under CVC 26708(d), you can install clear, colorless, transparent material on any window, including the windshield and front side windows, if the film meets all of the following:3California Legislative Information. Vehicle Code 26708
- Light transmission: the film alone allows at least 88 percent of visible light through, and the window as a whole still transmits at least 70 percent
- UV protection: the material is designed and manufactured to block the sun’s ultraviolet A rays
- Installer certificate: a certificate signed by the installing company (or by the manufacturer, if you installed it yourself) is kept in the vehicle, listing the installer’s or manufacturer’s full name and street address
- Condition: film that tears, bubbles, or wears enough to obstruct vision must be removed or replaced
Modern ceramic and UV-rejection films can block over 99 percent of UV radiation while remaining nearly invisible. For conditions like lupus or photosensitivity where UV exposure is the core problem, this route avoids the medical paperwork entirely. The tradeoff: the film won’t noticeably darken the window, so it does little for glare or visible-light sensitivity.
Traffic Stops and Citations Without Documentation
At a traffic stop, the statute contemplates that the driver or front-seat passenger will have the physician’s letter in the vehicle. Keep the original somewhere consistent and reachable, such as clipped to your registration and insurance. If you also installed clear UV film under subdivision (d), keep that installer’s certificate in the same spot. A clear plastic sleeve helps the paper hold up.
If you’re cited despite valid documentation, you can present the letter to the court to contest the ticket. A specific letter naming the condition is far more persuasive to a judge than a generic note.
Without an exemption, illegal tint typically results in a correctable violation, commonly called a fix-it ticket. The officer cites you, you have a set period to bring the tint back to legal levels, and once the correction is verified you pay a $25 administrative fee to the court to dismiss the ticket.4California Courts. Fix-It Ticket Ignore it, and the court can convert the correctable violation into a standard infraction with a base fine that, after California’s penalty assessments and surcharges, typically runs well over $100. Each subsequent stop can bring another citation.
If you have a legitimate medical need, the clean sequence is the letter first, the installation second, and the paperwork in the car from day one.