Massachusetts Housing & Shelter Alliance | 1,487 followers on LinkedIn. The Massachusetts Housing & Shelter Alliance (MHSA) is a nonprofit organization dedicated to ending homelessness in MA. | The Massachusetts Housing & Shelter Alliance's (MHSA) mission is to end homelessness through advocacy, collaboration, education, housing, and the implementation of outcome-based programs. MHSA is dedicated to innovative solutions that reduce public reliance on emergency resources. Founded in 1988, MHSA now has a membership of nearly 100 community-based agencies statewide.