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Wisconsin car seat laws

Wis. Stat. § 347.48(4) · Last checked September 23, 2026

Car seat stages

The statute text comes first. Numbers are a summary for comparison, not a replacement for the law.

Rear-facing seat

Statute text

If the child is less than one year old or weighs less than 20 pounds, the child shall be properly restrained in a rear-facing child safety restraint system, positioned at a designated seating position in a back passenger seat of the vehicle if the vehicle is equipped with a back passenger seat.

§ 347.48(4)(as)1.

What the law sets

Rear-facing seat required by law
Yes
Rear-facing until age
1 year
Rear-facing until weight
20 lb
Rear-facing until height
Not addressed in statute

Not set in § 347.48(4)(as)1.

Leaving rear-facing
Every listed limit must be met

The rule covers a child under one OR under 20 pounds, so a child must be at least one AND at least 20 pounds to move to a forward-facing seat.

Recommended (not law)

NHTSA

Children under age 1 should always ride in a rear-facing car seat. Keep your child rear-facing as long as possible — it's the best way to keep them safe — until they reach the top height or weight limit allowed by the car seat's manufacturer.

NHTSA – Car Seats and Booster Seats

AAP

All infants should ride rear-facing, starting with their first ride home from the hospital, and should continue riding rear-facing as long as possible until they reach the highest weight or height allowed by their car safety seat's manufacturer.

HealthyChildren.org (AAP) – Car Safety Seats: Information for Families

Forward-facing harness seat

Statute text

Subject to subd. 1., if the child is at least one year old and weighs at least 20 pounds but is less than 4 years old or weighs less than 40 pounds, the child shall be properly restrained as provided in subd. 1. or properly restrained in a forward-facing child safety restraint system, positioned at a designated seating position in a back passenger seat of the vehicle if the vehicle is equipped with a back passenger seat.

§ 347.48(4)(as)2.

What the law sets

Forward-facing harness required by law
Yes
Harness until age
4 years
Harness until weight
40 lb
Harness until height
Not addressed in statute

Not set in § 347.48(4)(as)2.

Leaving the harness
Every listed limit must be met

The rule covers a child under four OR under 40 pounds, so a child must be at least four AND at least 40 pounds to move to a booster.

Recommended (not law)

NHTSA

Once a child outgrows the rear-facing car seat, they are ready for a forward-facing car seat with a harness and tether. Keep the child in the forward-facing seat until they reach the top height or weight limit allowed by the car seat's manufacturer, then move to a booster seat, still in the back seat.

NHTSA – Car Seats and Booster Seats

AAP

Children should use a forward-facing car seat with a harness after outgrowing the rear-facing weight or height limit. It is best for children to ride in a seat with a harness as long as possible, at least to 4 years of age.

HealthyChildren.org (AAP) – Car Safety Seats: Information for Families

Booster seat

Statute text

Subject to subds. 1. and 2., if the child is at least 4 years old but less than 8 years old, weighs at least 40 pounds but not more than 80 pounds, and is not more than 57 inches in height, the child shall be properly restrained as provided in subd. 2. or properly restrained in a child booster seat.

§ 347.48(4)(as)3.

What the law sets

Booster required by law
Yes

A child booster seat or a forward-facing child safety restraint system is required.

Booster until age
8 years
Booster until weight
80 lb

The rule covers a child weighing "not more than 80 pounds", so a child of exactly 80 pounds is still covered.

Booster until height
57 in (4 ft 9 in)

The rule covers a child "not more than 57 inches" tall, so a child of exactly 57 inches is still covered.

Leaving the booster
Meeting any one listed limit is enough

The rule applies only while the child is under eight AND 80 pounds or less AND 57 inches or less, so passing any one of those ends it.

Recommended (not law)

NHTSA

Keep your child in a booster seat until they are big enough to fit in a seat belt properly — the lap belt lying snugly across the upper thighs (not the stomach) and the shoulder belt snug across the shoulder and chest (not the neck or face).

NHTSA – Car Seats and Booster Seats

AAP

All children whose weight or height exceeds the forward-facing limit for their car safety seat should use a belt-positioning booster seat until the vehicle seat belt fits properly, typically when they have reached 4 feet 9 inches in height and are 8 to 12 years of age.

HealthyChildren.org (AAP) – Car Safety Seats: Information for Families

Seat belt

Statute text

Subject to subds. 1. to 3., if the child is less than 8 years old, the child shall be properly restrained as provided in subds. 1. to 3. or properly restrained in a safety belt approved by the department under sub. (2).

§ 347.48(4)(as)4. From age eight, § 347.48(2m)(c) requires each passenger at a belt-equipped seating position to be properly restrained in a safety belt.

What the law sets

Seat belt alone from age
8 years
Seat belt alone from height
57 in (4 ft 9 in)

Above 57 inches a child is outside the booster rule in § 347.48(4)(as)3.

Moving to the seat belt
A combination of conditions (see statute text)

A child may use the belt alone from age eight, or earlier on passing 80 pounds or 57 inches; the belt stage has no weight field, so the condition is written out.

Moving to the seat belt — conditions
age>=8yr OR weight>=80lb OR height>=57in

Recommended (not law)

NHTSA

Once a child is big enough to fit in a seat belt properly, they can ride with just the lap-and-shoulder belt, but should still ride in the back seat — NHTSA recommends keeping children in the back seat at least through age 12.

NHTSA – Car Seats and Booster Seats

AAP

Children should transition to the vehicle seat belt once it fits properly, typically at about 4 feet 9 inches in height and 8 to 12 years of age; all children younger than 13 years should ride in the back seat.

HealthyChildren.org (AAP) – Car Safety Seats: Information for Families

Front seat

Many states have no front-seat age in statute. Where that is the case, we say so and cite the section we read.

Front seat — statute text
If the child is less than one year old or weighs less than 20 pounds, the child shall be properly restrained in a rear-facing child safety restraint system, positioned at a designated seating position in a back passenger seat of the vehicle if the vehicle is equipped with a back passenger seat.

§ 347.48(4)(as)1. The same back-seat requirement is repeated in § 347.48(4)(as)2 for the forward-facing stage; the booster and belt stages have none.

Minimum age for the front seat
4 years

The back-seat requirement in § 347.48(4)(as)1 and 2 covers children under four years or under 40 pounds; there is no front-seat rule for older children.

Conditions
Applies only if the vehicle is equipped with a back passenger seat, and only to children who must ride in a rear-facing or forward-facing child safety restraint system (under four years or under 40 pounds).

Penalties

What a car seat ticket costs, and whether showing proof of a proper seat can cancel it.

First offense — fine
$10 – $75

§ 347.50(3)(a): $30 to $75 if the child is under four. § 347.50(4): $10 to $25 for a first offense if the child is at least four and under eight.

Repeat offense — fine
$25 – $200

§ 347.50(4): $25 to $200 for a second or later conviction within three years involving a child at least four and under eight. For a child under four, § 347.50(3)(a) sets $30 to $75 for every offense.

License points
None

Wis. Admin. Code Trans 101.02(5)(a): the department may not assess demerit points for a child safety restraint violation.

Fine waiver
For a child under four, no forfeiture may be assessed if the vehicle had no compliant child safety restraint system when the citation was issued, the person proves one was bought or leased and properly installed within 30 days, and the person has had no such citation in the previous three years (§ 347.50(3)(b)).

Exemptions

Exempt means the statute excludes it. Silent means the statute does not address it.

Taxis
Exempt

§ 347.48(4)(c): the subsection does not apply if the motor vehicle is a motor bus, school bus, taxicab, moped or motorcycle.

Rideshare (Uber, Lyft)
Not addressed in statute

§ 347.48(4) does not name transportation network companies; (4)(c) names taxicabs.

Buses
Exempt

§ 347.48(4)(c) excludes motor buses and school buses by name.

Medical exemption
Not addressed in statute

Only by rule: § 347.48(4)(b) lets the department exempt by rule a child who because of a physical or medical condition or body size cannot be placed in a child safety restraint system, booster seat or safety belt. § 347.48(4)(b) only authorises the department to create such an exemption by rule; no promulgated rule is cited here, so the statute itself does not exempt a child on medical grounds.

Out-of-state vehicles
Not addressed in statute

§ 347.48(4) does not address nonresident drivers or out-of-state vehicles.

How Wisconsin compares

Wisconsin is tied for 6th of 47 jurisdictions with a numeric booster age: 33 jurisdictions, including Wisconsin, require a booster until age 8.

Compared with Illinois, Iowa, Michigan, and Minnesota, Wisconsin differs on: rear-facing rules (from Illinois, Michigan, and Minnesota), booster rules (from Illinois, Iowa, Michigan, and Minnesota), and front-seat rules (from Illinois, Iowa, Michigan, and Minnesota).

Law compared with the AAP recommendation

  • Wisconsin law: a rear-facing seat is required until the child reaches age 1 and 20 lb. AAP recommends: All infants should ride rear-facing, starting with their first ride home from the hospital, and should continue riding rear-facing as long as possible until they reach the highest weight or height allowed by their car safety seat's manufacturer.
  • Wisconsin law: a forward-facing harness seat is required until the child reaches age 4 and 40 lb. AAP recommends: Children should use a forward-facing car seat with a harness after outgrowing the rear-facing weight or height limit. It is best for children to ride in a seat with a harness as long as possible, at least to 4 years of age.
  • Wisconsin law: a booster seat is required until the child reaches age 8, 80 lb, or 57 in, whichever comes first. AAP recommends: All children whose weight or height exceeds the forward-facing limit for their car safety seat should use a belt-positioning booster seat until the vehicle seat belt fits properly, typically when they have reached 4 feet 9 inches in height and are 8 to 12 years of age.
  • Wisconsin law: a child may use the seat belt alone once this condition is met: age ≥ 8 yr or weight ≥ 80 lb or height ≥ 57 in. AAP recommends: Children should transition to the vehicle seat belt once it fits properly, typically at about 4 feet 9 inches in height and 8 to 12 years of age; all children younger than 13 years should ride in the back seat.

See every state side by side on the comparison pages.

Guides covering Wisconsin

Sources

State law comes from the statute or state agency below. Recommendations come from NHTSA and the American Academy of Pediatrics. The responsible agency is Wisconsin Department of Transportation.

State law

Recommendations

Disclaimer

This page summarizes Wisconsin law for reference. It is not legal or medical advice. The statute text is the law; the numbers are our summary of it. Legal minimums are not safety recommendations: NHTSA and the AAP recommend keeping a child in each stage for as long as the seat allows. Check the statute or Wisconsin Department of Transportation before relying on anything here.