Focused on non-profit:
American Association of Homes and Services for the Aging (AAHSA) www.aahsa.org
"Our 5,700 member organizations ...offer the continuum of aging services: adult day services, home health, community services, senior housing, assisted living residences, continuing care retirement communities and nursing homes."
In Pennsylvania there is http://panpha.org/
Focused on both for-profit and non-profit providers:"Our members – nonprofit providers of long-term care and aging services"
International Association of Homes and Services for the Aging (IASHSA) www.iahsa.net
"represents more than 20,000 ageing services providers worldwide who serve almost 5 million elderly daily."
American Health Care Association (AHCA) www.ahcancal.org
"the nation’s largest association of long term and post-acute care providers...advocates for quality care and services for frail, elderly and disabled Americans"
National Investment Center for the Seniors Housing and Care Industry (NIC) www.nic.org
"resource to lenders, investors, developers/operators, and others interested in meeting the housing and care needs of America's seniors"