From carf.org:
Why does accreditation matter?
Consumers face a variety of options when deciding what services to use and who should provide them. Accreditation is a sign of quality and is an important consideration in their decision making. They look for CARF® accreditation in their choice of treatment for addiction and substance abuse, rehabilitation of a disability, home and community services, retirement living, and other health and human services.
Achieving accreditation requires a service provider to commit to quality improvement, focus on the unique needs of each person the provider serves, and monitor the results of services.