• Missouri law requires child restraint device use through age 7.missouri outline image by Kim Jones from Fotolia.com
  
  As of May 2010, Missouri is one of 47 states with a booster seat provision in their child restraint law, according to the Governors Highway Safety Association. While the state uses a tiered system in relation to age and size and offers some exclusions, generally, you must secure your child in a child-passenger safety system until her 8th birthday.
  
  

Age and Size Parameters

• Missouri's child passenger restraint law requires use of an appropriate child restraint device for all children less than 4 years of age. The same requirement applies to all children who weigh less than 40 pounds, regardless of age. You must secure children between the ages of 4 and 7 who weigh at least 40 pounds, but less than 80 pounds, and are less than 4 feet 9 inches tall. These children must be secured in a child-passenger restraint system, typically a booster seat. If your child is older than 4 and weighs 80 pounds or more, or measures more than 4 feet 9 inches, Missouri gives you the option of using a booster seat or adult seat belt. Missouri permits adult seat belt use for all children between 8 and 16, according the Insurance Institute for Highway Safety states.
  
  

Exemptions

• Under Missouri law, you can transport a child in the back seat of your motor vehicle without a booster seat, if your vehicle is only equipped with lap belts. Booster seats can only be used with shoulder/lap belts. In situations where you are transporting children in your immediate family and the number of children is greater than the number of seating positions, children who are not using a child restraint device may be located behind the front seat.
  
  

Enforcement

• If you violate Missouri's child restraint law, you have committed an infraction. The state levies a fine of $50 plus court costs for violating the car seat and booster seat segments of the child-passenger safety regulations. If you break the seat belt portion of the law--which covers children older than 4 years of age, weighing 80 pounds or more and taller than 4 feet 9 inches--Missouri can hit you with a $10 fine. The law does not apply to "public carrier[s] for hire," such as taxis, public transit buses or school buses.