Each state regulates requirements for people who work in child care. Some states note that a licensed child care worker must be at least 18 years old. Others require that a person have a high school diploma to get certified, which means candidates must often be at least 18.
The role a person plays in a day care impacts requirements. A person who cleans or prepares meals, but does not directly work with children may not need to be a certain age. Some states require teachers who work directly with children to obtain national certification, which may involve completing a one- or two-year degree program. In these states, qualified candidates are often at least 19 or 20.