On June 13, 2018, the Boston City Council passed a new Ordinance that will prohibit investors from engaging in short-term rentals of their units. Homeowners, on the other hand, will still be allowed to rent out their homes by the night, and owner-occupants of two-family and three-family houses will be permitted to rent out one unit.
The new rules go into effect on January 1, 2019. However, the regulations will not apply to current short-term rental hosts until September 2019. Policing who is an investor and who is an owner will be a challenge for the City of Boston. Other large cities, such as Brookline and Cambridge, may also enact restrictive ordinances to limit investors to buy and use their real estate for short term rentals.
For more information, please read this article from the Boston Globe.