United Behavioral Health, a company that administers mental health benefits for a large number of employers, HMOs, PPOs, and state and local agencies, refuses to include Narconon in its list of providers because Narconon is not accredited by JCAHO, the Joint Commission on Accreditation of Healthcare Organizations.
You can verify this by going to the JCAHO Quality Check page and typing "Narconon" into the Organization Name search box. (For comparison, type "Wellspring" in the search box to see what an approved program looks like.)
Narconon Arrowhead is accredited by CARF, the Commission on Accreditation of Rehabilitation Facilities, a second-rate outfit that is in no way equivalent to JCAHO. No other Narconon facility is accredited by anyone.
Narconon Arrowhead's accreditation by CARF was handled by William Kent McGregor, who later joined Narconon staff, and has had some interesting legal problems. Here's the docket from that case.