With the start of the 2019 flying season the FAA has put new rules in place for the registration of UAV.
The registration is required for all RC craft heaver then .55lb (250g). if you have not registered yet it is easy to do.
The FAA registration is $5 and is good for three years. you do not need to register each UAV you own but you do need to have the FAA registration number on the outside of the craft.
FAA registration Site
Do not register as PART 107 unless you are doing commercial operationshttps://www.faa.gov/uas/getting_started/register_drone/