Iowa has some of the strictest window tint rules for the front of your vehicle, but it’s very relaxed on the rear windows. This guide explains the main Iowa window tint laws in simple language so you know what is legal before you tint.
Quick Rules at a Glance
- Applies to everyone: Iowa’s tint rules apply to any vehicle operated on Iowa roads,
no matter where it is registered. - Front windshield: Must let in at least 70% of visible light (about as clear as stock glass).
A narrow, non-reflective strip is allowed along the top, above the AS-1 line (or similar line)
but the main viewing area must still meet the 70% standard. - Front side windows (driver & passenger): Must also meet a minimum
70% light transmittance. That means very little or no added tint film on these windows. - Back seat side windows: Any darkness is allowed.
- Rear window (back glass): Any darkness is allowed.
- Reflectivity: Front glass cannot be excessively reflective; mirror-like films are not allowed.
The rule is written as “not excessively dark or reflective,” not a specific percentage. - Medical exemptions: No new medical exemptions have been allowed since
July 4, 2012. Only certain grandfathered exemptions from before that date still count. - Fine: A violation of the tint section is a scheduled equipment offense, typically a
flat fine around $70 before court costs and surcharges.
In plain terms: keep the front windshield and front doors basically clear (70%+), and you can go
as dark as you want on the back doors and rear glass.
What “70%” Actually Means (VLT)
Tint darkness is measured with Visible Light Transmission (VLT).
- VLT = the percentage of visible light that passes through the glass plus any film.
- Higher VLT (for example 70%) = lighter tint, easy to see through.
- Lower VLT (for example 20%) = darker tint, hard to see through.
Iowa’s law says the front windshield and front side windows must have at least
70% light transmittance. That is the combined result of the glass and whatever film is on it.
Most factory glass is already slightly tinted, so even a light film can drop you below 70%.
Windshield Tint Rules in Iowa
The windshield is the most strictly controlled window on the vehicle.
- You may not drive with a windshield that “does not permit clear vision.”
- By rule, the windshield must meet a minimum standard of
70% light transmittance for legal tint. - You may apply non-reflective tint only:
- Above the manufacturer’s AS-1 line, or
- In a narrow band at the very top of the glass where the AS-1 line would normally be.
- The rest of the windshield must remain essentially clear to the eye.
In everyday terms, think of a small, light strip at the top of the windshield and
no dark film on the main viewing area.
Front Side Windows (Driver & Passenger)
This is where Iowa is especially strict compared with many other states.
- The front side windows (to the immediate right and left of the driver) must meet a
70% light transmittance standard. - The law defines “excessively dark or reflective” as anything that fails that 70% standard.
- Most aftermarket tints like 35%, 20%, or 5% (“limo”) will make these windows
too dark to be legal. - Even a “70% film” on glass that already blocks some light can test below the 70% requirement,
so you should be extremely careful adding film to the front doors.
Realistically, the safest route in Iowa is to leave the front side windows
untinted or with only very light, legal film installed by a shop that can meter it.
Rear Side Windows & Rear Window
Behind the driver, Iowa is very lenient.
- Rear side windows (back doors): Any darkness is legal.
- Rear window (back glass): Any darkness is legal.
- There is no specific VLT minimum for these windows in the rule; Iowa focuses on the front.
- If your rear window is very dark, it is still wise to have good side mirrors for safety,
even though Iowa law does not explicitly tie mirror requirements to tint darkness.
This means a very common Iowa setup is:
clear or nearly clear up front and dark tint on the rear doors and rear glass.
Medical Exemptions in Iowa
Iowa used to allow medical exemptions for darker front tint, but that changed in 2012.
- Before July 4, 2012, people with certain light-sensitive conditions could obtain a
DOT medical exemption (Form 432020) allowing front glass between 35% and 70% VLT. - As of July 4, 2012:
- No new medical exemptions may be granted.
- Existing exemptions from before that date remain valid only if:
- The vehicle still transports the specific person named on the form, and
- The original DOT Form 432020 is carried in the vehicle.
- Once that person no longer uses the vehicle, the exemption expires, and the car must be
returned to 70%+ transparency within 60 days.
- If you developed a light-sensitive condition after July 4, 2012, Iowa does not offer a
special tint exemption. Everyone is held to the same 70% rule up front.
So unless you have one of those rare, older exemption forms and still meet all conditions,
you should assume there is no medical waiver available.
Reflectivity, Colors & Stickers
Iowa’s law focuses more on darkness than on color, but reflectivity still matters.
- Reflectivity: For the front windshield and front side windows, the rule says they
cannot be excessively reflective. Mirror-style or chrome-like films on the front are
asking for a ticket. - Rear windows: There’s no precise reflectivity percentage written, but heavily mirrored
finishes can still be viewed as “excessive.” - Color: Iowa law does not list specific banned tint colors; however, unusual or
bright colors (especially anything resembling emergency lights) may draw extra attention. - Manufacturer certification: Film makers are not required to certify their
tint specifically for Iowa. - Stickers: Iowa does not require a tint-compliance sticker on the glass, although
many shops add their own small label.
Penalties for Illegal Tint in Iowa
Violating the tint standard is treated as an equipment violation.
- A window that does not meet the required 70% standard on the windshield or front side windows can
lead to a citation under Iowa Code 321.438. - The scheduled fine is typically around $70 before surcharges and court costs.
- You may be required to remove or replace the tint to bring the vehicle into compliance.
- Because only the front glass is regulated, most citations involve:
- Dark film on the front doors, or
- Dark film down into the main area of the windshield.
While the fine may not be huge, repeat stops and the cost of stripping and redoing tint quickly add up.
Is Your Iowa Tint Probably Legal?
Use this quick checklist as a rough guide:
- Windshield:
- Only a light, non-reflective strip at the very top (above the AS-1 line)?
- No dark film across the main field of view?
- Front side windows (driver & passenger):
- Do they look basically clear to the eye?
- If film was added, is it marketed as very light (around 70% VLT) and did a shop meter it?
- Anything like 35%, 20%, or 5% tint here is almost certainly illegal.
- Back seat side windows & rear window:
- Any darkness is OK in Iowa, so 20% or even 5% is legal on these windows.
- Medical exemption?
- If you are relying on a medical exemption, was it issued before July 4, 2012 and do you
still carry DOT Form 432020 in the vehicle? - If not, assume no exemption applies.
- If you are relying on a medical exemption, was it issued before July 4, 2012 and do you
- Reflectivity & color:
- No mirror-like chrome film on the front?
- Neutral charcoal/gray look instead of bright colors?
If your tint is close to the limit, the only way to be absolutely sure is to have it checked with a
tint meter by a reputable shop, inspection station, or law enforcement.
Important Legal Note
This page is a plain-language summary of Iowa’s window tint rules based on
Iowa Code 321.438 and the Iowa DOT “Window Tinting Standards”. It is
not formal legal advice and may not cover every special case or future change (there have been
recent bills proposed to relax the 70% rule, but they have not taken effect as of now).
For serious questions, a ticket you want to contest, or a very custom setup, you should read the current
statute text and check with the Iowa DOT, Iowa State Patrol, or a local attorney.
Summary
To stay comfortable and legal on Iowa roads:
- Keep your front windshield and front side windows at 70% VLT or lighter.
- Use only a thin, non-reflective strip at the top of the windshield.
- Feel free to go much darker on the rear side windows and rear glass, if you like.
- Avoid mirror-like films, especially on the front.
- Don’t assume you can get a medical waiver; Iowa stopped issuing new ones in 2012.
Follow these guidelines and you can enjoy the benefits of tint while staying on the right side of Iowa law.