The reality is that the cost of sober living is not covered by insurance in the state of California. Since there is no licensed certification offered by the State of California for a halfway house or aftercare or any sort of sober living, these services are incapable of obtaining insurance contracts.
Having said that, a lot of outpatients and treatment centers offer persons subsidized or free rent in sober living in the event that their program is attended by their clients. Be careful as this is an unclear situation. A lot of such programs just give sober living due to the fact that it makes their clients convenient, but there is usually little care and supervision in such care programs.