Mass. Gen. Laws ch. 272 § 92A
No owner, lessee, proprietor, manager, superintendent, agent or employee of any place of public accommodation, resort or amusement shall, directly or indirectly, by himself or another, publish, issue, circulate, distribute or display, or cause to be published, issued, circulated, distributed or displayed, in any way, any advertisement, circular, folder, book, pamphlet, written or painted or printed notice or sign, of any kind or description, intended to discriminate against or actually discriminating against persons of any religious sect, creed, class, race, color, denomination, sex, gender identity, sexual orientation, which shall not include persons whose sexual orientation involves minor children as the sex object, nationality, or because of deafness or blindness, or any physical or mental disability, in the full enjoyment of the accommodations, advantages, facilities or privileges offered to the general public by such places of public accommodation, resort or amusement.
A place of public accommodation, resort or amusement within the meaning hereof shall be defined as and shall be deemed to include any place, whether licensed or unlicensed, which is open to and accepts or solicits the patronage of the general public and, without limiting the generality of this definition, whether or not it be (1) an inn, tavern, hotel, shelter, roadhouse, motel, trailer camp or resort for transient or permanent guests or patrons seeking housing or lodging, food, drink, entertainment, health, recreation or rest; (2) a carrier, conveyance or elevator for the transportation of persons, whether operated on land, water or in the air, and the stations, terminals and facilities appurtenant thereto; (3) a gas station, garage, retail store or establishment, including those dispensing personal services; (4) a restaurant, bar or eating place, where food, beverages, confections or their derivatives are sold for consumption on or off the premises; (5) a rest room, barber shop, beauty parlor, bathhouse, seashore facilities or swimming pool, except such rest room, bathhouse or seashore facility as may be segregated on the basis of sex; (6) a boardwalk or other public highway; (7) an auditorium, theatre, music hall, meeting place or hall, including the common halls of buildings; (8) a place of public amusement, recreation, sport, exercise or entertainment; (9) a public library, museum or planetarium; or (10) a hospital, dispensary or clinic operating for profit; provided, however, that with regard to the prohibition on sex discrimination, this section shall not apply to a place of exercise for the exclusive use of persons of the same sex which is a bona fide fitness facility established for the sole purpose of promoting and maintaining physical and mental health through physical exercise and instruction, if such facility does not receive funds from a government source, nor to any corporation or entity authorized, created or chartered by federal law for the express purpose of promoting the health, social, educational vocational, and character development of a single sex; provided, further, that with regard to the prohibition of sex discrimination, those establishments which rent rooms on a temporary or permanent basis for the exclusive use of persons of the same sex shall not be considered places of public accommodation and shall not apply to any other part of such an establishment. An owner, lessee, proprietor, manager, superintendent, agent or employee of any place of public accommodation, resort or amusement that lawfully segregates or separates access to such place of public accommodation, or a portion of such place of public accommodation, based on a person's sex shall grant all persons admission to, and the full enjoyment of, such place of public accommodation or portion thereof consistent with the person's gender identity.
Any person who shall violate any provision of this section, or who shall aid in or incite, cause or bring about, in whole or in part, such a violation shall be punished by a fine of not more than one hundred dollars, or by imprisonment for not more than thirty days, or both.
Mass. Gen. Laws ch. 272, § 92A