Revenue code
Revenue Code 1001: Residential Treatment, Psychiatric
Revenue code 1001 is psychiatric residential treatment. How mental health and eating disorder residential programs bill it, and the denials to expect.
Last reviewed October 2026
Meaning
1001: Behavioral health accommodations: residential treatment, psychiatric
When facilities use 1001
1001 sits in the 100X behavioral health accommodations range. Mental health residential and eating disorder residential programs bill it as a per day accommodation line. Substance use residential uses 1002 instead.
Other codes in the range: 1003 supervised living, 1004 halfway house, 1005 group home and 1006 outdoor or wilderness behavioral health, effective July 1, 2017.
HCPCS and type of bill
| Payer guide | What it asks for |
|---|---|
| Evernorth Behavioral Health | 1001 for mental health and eating disorder residential, no HCPCS; dual diagnosis may use 1001 or 1002 |
| BCBS of Mississippi | 1001 as an accommodation line, number of days as units, type of bill 086X |
Some payers ask for a HCPCS such as H0018 on residential lines. Many do not. The payer's guide decides.
Common denials and fixes
- Medical necessity at concurrent review. CO-50. In California, 79% of residential treatment denials that reached DMHC external review in 2021 to 2026 were overturned (an upper bound).
- Days past the authorization. CO-198. Track auth end dates daily.
- Plan excludes residential. CO-96 or CO-204. Check benefits before admission.
- SUD diagnosis on a 1001 line. CO-11. Use 1002 for substance use residential.
Questions
Is revenue code 1001 for substance use residential?
No. 1001 is psychiatric residential. Substance use residential is 1002.
Does 1001 need a HCPCS code?
It depends on the payer. Evernorth lists none for residential; others may ask for one.
Sources
- Noridian Healthcare Solutions (Medicare contractor), Revenue codes (opens in a new tab)
- Evernorth Behavioral Health, Authorization and Billing Resource (PDF) (opens in a new tab)
- Blue Cross & Blue Shield of Mississippi, Behavioral Health Coding Policy (opens in a new tab)
Educational summary, not billing advice. Your contract and the payer's current guide decide how to bill.