Horizon Homes Inc. was the first community-based group home in Western Pennsylvania for people with intellectual and developmental disabilities. It was incorporated on March 12, 1969 with charter members Roger Buchanan, Irvin Chamovitz, Patricia Clapp, Vigdor Kavalier, Rabbi Walter Jacob, Irene Jacob, Murray Levine, and Stanley H. Levin.
Rabbi Walter and Irene Jacob of Rodef Shalom Congregation conceived of Horizon Homes project in 1968, when their daughter Claire “Poopsie” Jacob needed permanent living accommodations following an extended stay at the D. T. Watson Home. Unsatisfied with the conditions at state-run institutions, and wanting a community-based option that would accommodate regular visitation, they convened a local delegation in October 1968 to tour emerging group homes in Connecticut. Following a fundraising campaign and a zoning dispute, Horizon Homes opened its first facility at 1212 N. Negley Ave. in the East End in 1972 and subsequently opened other facilities in the area.
Horizon Homes joined with Idlewood Center in 1999 to become Mainstay Life Services.