From an ordinance enacted last week:
The city, recognizing its commitment to nondiscrimination and fair treatment of its citizens and employees, adopts this ordinance acknowledging domestic partnerships. The ordinance allows persons in committed relationships who meet the criteria established by the city as constituting domestic partnerships to register at the office of the city clerk and obtain a certificate attesting to their status….
[Definitions:] (c) Domestic partnership means the entity formed by people who meet the following criteria and jointly file a registration statement proclaiming that:
(1) They are in a relationship of mutual support, caring and commitment and intend to remain in such a relationship; and
(2) They reside together; and
(3) They are not married; and
(4) They are not related by blood closer than would bar marriage in the Commonwealth of Massachusetts; and
(5) They are competent to contract; and
(6) They consider themselves to be a family.
(d) Mutual support means that the domestic partners each contribute in some fashion to the maintenance and support of the domestic partnership.
(e) Reside together means living together in a common household. A partner may be temporarily absent from the common household, so long as they have the intent to return. A partner may own or maintain an additional residence.
[Rights of domestic partnership:] (a) When the term “spouse” or “marriage” is used in other city ordinances, it shall be interpreted to include a domestic partner or partnership. When the term “family” is used in other city ordinances, it shall be interpreted to include domestic partnerships.
(b) The City of Somerville shall afford persons in domestic partnerships all the same rights and privileges afforded to those who are married…
According to Boston.com (Ellen Barry),
Under the new ordinance, city employees in polyamorous relationships would be able to extend health benefits to multiple partners. But it is not clear, Davis said, whether private employers will follow the city’s lead.
The article describes the ordinance as recognizing “polyamorous relationships,” so it sounds like that was its primary focus. But in principle this could apply to housemates, so long as the members are willing to describe themselves as “family.” Likewise, it could apply to religious communes or monastery-like organizations or perhaps even fraternities and sororities, if they are willing to so describe themselves as families—not that big a leap from “brother” and “sister,” I think. (I assume that sharing expenses for rent, food, and the like, would qualify as “mutual support,” since it “contribute[s] in some fashion to the maintenance and support of the domestic partnership.”) This suggests that someone who lives in a ten-person fraternity or fraternal order or commune and is a city employee could get health insurance coverage for all the “domestic partners.”
Oddly, though, traditional families related by blood or marriage are categorically excluded: If six mutually supporting housemates are willing to declare themselves a “family,” they can all become domestic partners and benefit from the health insurance offered to one of them. But if six siblings who live together (or three siblings and their spouses or lovers who all live together) want to do the same, they can’t get the same benefit. Thanks to commenter Dr. Ed for the pointer.