Moped/motorized bicycle owners are required to obtain and display a rear license plate. Moped/Motorized Bicycle License. Applicants age 14-15, or anyone without a valid driver license, must pass vision, knowledge, and road tests to obtain a moped license. Probationary licenses are required for 14- and 15-year-old operators. Gas-powered mopeds with engines larger than 50cc are not allowed. Electric mopeds are also subject to regulations – their engines must not exceed 4,476 watts of power. The good news is that you don’t need a special license to operate a moped in Colorado. Do I need a motorcycle license for a 150cc scooter in Colorado?
It appears to me that scooters up to 50cc can be operated as 'motorized bicycles'. As long as they don't go faster than 30 mph. These vehicles are registered as such, but no special license is required. Larger than that is a 'motorcycle', and they must be registered and you need a motorcycle endorsement.

Motorcycle permit or license. Commercial learner’s permit or driver’s license. If you don’t have any of the above credentials, you can apply for a Class E Moped License by heading to your circuit court clerk’s office, where you’ll need to: Submit: A moped license application (available at the circuit court clerk’s office).

In PA you need a regular driver's license to ride a 49cc. You are considered a motor vehicle and follow the same traffic laws as a car or motorcycle, so no riding in the bike lane. This might help. It's the PennDOT Motorcycle Operator Manual. Most states require owners to register any scooter, moped, or motorized bike with a 50cc or larger engine. Keep in mind this is on a general rule of thumb. Some states, like California, require residents to register every type of scooter and moped, except a motorized bike with pedals (as long as the motor is electric and no more than 1,000 watts). . 140 363 138 19 4 149 399 66 37

does a 50cc moped need a license