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Missouri car seat laws

Mo. Rev. Stat. § 307.179 · 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

Not addressed in statute.

Not set in § 307.179; subsection 2(1) and 2(2) require a child passenger restraint system appropriate for the child, without naming a rear-facing or forward-facing harness seat.

What the law sets

Rear-facing seat required by law
Not addressed in statute

Not set in § 307.179; subsection 2(1) and 2(2) require a child passenger restraint system appropriate for the child, without naming a rear-facing or forward-facing harness seat.

Rear-facing until age
Not addressed in statute

Not set in § 307.179.

Rear-facing until weight
Not addressed in statute

Not set in § 307.179.

Rear-facing until height
Not addressed in statute

Not set in § 307.179.

Leaving rear-facing
Not addressed in statute

Not set in § 307.179.

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

Not addressed in statute.

Not set in § 307.179; subsection 2(1) and 2(2) require a child passenger restraint system appropriate for the child, without naming a rear-facing or forward-facing harness seat.

What the law sets

Forward-facing harness required by law
Not addressed in statute

Not set in § 307.179; subsection 2(1) and 2(2) require a child passenger restraint system appropriate for the child, without naming a rear-facing or forward-facing harness seat.

Harness until age
Not addressed in statute

Not set in § 307.179.

Harness until weight
Not addressed in statute

Not set in § 307.179.

Harness until height
Not addressed in statute

Not set in § 307.179.

Leaving the harness
Not addressed in statute

Not set in § 307.179.

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

Children at least four years of age but less than eight years of age, who also weigh at least forty pounds but less than eighty pounds, and who are also less than four feet, nine inches tall, shall be secured in a child passenger restraint system or booster seat appropriate for that child.

§ 307.179.2(3). Younger or lighter children fall under § 307.179.2(1) (under four, regardless of weight) and 2(2) (under 40 pounds, regardless of age), which require a child passenger restraint system.

What the law sets

Booster required by law
Yes

A booster seat or another child passenger restraint system is required.

Booster until age
8 years
Booster until weight
80 lb

The rule covers a child weighing less than 80 pounds, so a child of exactly 80 pounds is outside it.

Booster until height
57 in (4 ft 9 in)

The rule covers a child "less than four feet, nine inches" tall, so a child of exactly 57 inches is outside it.

Leaving the booster
Meeting any one listed limit is enough

The rule applies only while the child is under eight AND under 80 pounds AND under 4 feet 9 inches, so reaching 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

Children at least eighty pounds or children more than four feet, nine inches in height shall be secured by a vehicle safety belt or booster seat appropriate for that child.

§ 307.179.2(4). A child who would otherwise need a booster may use a lap belt alone in the back seat where that seat has no combination lap and shoulder belt (§ 307.179.2(5)).

What the law sets

Seat belt alone from age
Not addressed in statute

Not set in § 307.179.2(4); the belt stage turns on weight and height, not age.

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

The statute says "more than four feet, nine inches", so a child of exactly 57 inches is not yet in this stage on height alone.

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

The belt stage starts at 80 pounds or above 4 feet 9 inches; there is no belt weight field, so the condition is written out.

Moving to the seat belt — conditions
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
When transporting children in the immediate family when there are more children than there are seating positions in the enclosed area of a motor vehicle, the children who are not able to be restrained by a child safety restraint device appropriate for the child shall sit in the area behind the front seat of the motor vehicle unless the motor vehicle is designed only for a front seat area.

§ 307.179.2(6). This is the only front-seat rule in the section; there is no general minimum age.

Minimum age for the front seat
Not addressed in statute

No minimum front-seat age in § 307.179.

Conditions
Only where immediate-family children outnumber the seating positions: the children who cannot be properly restrained must sit behind the front seat, unless the vehicle has only a front seat area.

Penalties

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

First offense — fine
Up to $50

§ 307.179.3: a violation of subsection 2(1), (2) or (3) is an infraction punishable by a fine of not more than $50 and court costs. A violation of subsection 2(4) instead carries the § 307.178.6 penalty: a fine not to exceed $10 and no court costs.

Repeat offense — fine
Up to $50

§ 307.179.3 sets one range for every offense; there is no separate repeat penalty.

License points
None

Not set in § 307.179. The point schedule in § 302.302.1 does not list child restraint violations; its catch-all assesses 2 points for a moving violation not listed there, and § 307.178.6 bars points for violations of that seat belt section, whose penalty applies to § 307.179.2(4).

Fine waiver
If the driver provides evidence of acquiring a child passenger restraint system or child booster seat before or at the hearing, a citation under subsection 2(1), (2) or (3) is dismissed or withdrawn (§ 307.179.3).

Exemptions

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

Taxis
Exempt

§ 307.179.4: the section does not apply to any public carrier for hire.

Rideshare (Uber, Lyft)
Not addressed in statute

§ 307.179 does not name transportation network companies; subsection 4 exempts public carriers for hire.

Buses
Exempt

§ 307.179.4: the section does not apply to students four years of age or older riding a school bus designed for eleven or more passengers built or equipped to Missouri Minimum Standards for School Buses.

Medical exemption
Exempt

§ 307.178.2: the provisions of that section and of § 307.179 do not apply to persons who have a medical reason for failing to have a seat belt fastened about their body.

Out-of-state vehicles
Not addressed in statute

§ 307.179 does not address nonresident drivers or out-of-state vehicles.

How Missouri compares

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

Compared with Arkansas, Illinois, Iowa, Kansas, Kentucky, Nebraska, Oklahoma, and Tennessee, Missouri differs on: rear-facing rules (from Illinois, Iowa, Nebraska, Oklahoma, and Tennessee), booster rules (from Arkansas, Illinois, Iowa, Kentucky, Nebraska, Oklahoma, and Tennessee), and front-seat rules (from Nebraska).

Law compared with the AAP recommendation

  • Missouri law does not address this stage. 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.
  • Missouri law does not address this stage. 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.
  • Missouri 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.
  • Missouri law: a child may use the seat belt alone once this condition is met: 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.

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 Missouri Department of Transportation, Highway Safety and Traffic Division.

State law

Recommendations

Disclaimer

This page summarizes Missouri 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 Missouri Department of Transportation, Highway Safety and Traffic Division before relying on anything here.