For out of state residents the Florida Department of Highway and Safety does not require you to have a Florida license to register your car. But out of state residents must have FL proof of insurance before obtaining a license or registration renewal.
Florida insurance is required to meet the requirements of Florida Statutes. Only insurance issued or countersigned by a Florida agent is electronically reported to the Department of Highway Safety and Motor Vehicles for verification purposes.
Insurance companies' guidelines differ but most will allow you to get insurance on the vehicle you wish to register in FL without having a Florida license. It is understood there are situations in which you will have a car registered in Florida but carry an out of state driver's license.
One such scenario is a person who buys a car to keep at their Florida vacation home while keeping their license from their permanent state of residence. It appears you fall under this type of situation. If you wish to get a quote for Florida auto insurance with your Massachusetts license, follow this link.