Acute and Subacute Services Provided in an Institute for Mental Disease (IMD)
Customize your policy alerts
Sign up for all partners_health_management policy alerts
Know when partners_health_management releases new policies or updates existing guidance.
Monitor payer policy activity
Defines coverage, utilization management, clinical criteria, and operational requirements for 24-hour acute and subacute psychiatric and substance use inpatient services delivered in an Institute for Mental Disease (IMD) for Medicaid members ages 21-64.
No material clinical or coverage changes in this revision.
Coverage and Medical Necessity Criteria
inv-01: Preadmission Review Criteria — Substance Use Disorders
Covered when ANY of the following are met in a member with any DSM-5 substance use disorder diagnosis:
Preadmission review criteria for Medicaid members ages 21-64.
inv-02: Preadmission Review Criteria — Non-Substance Use Disorders
Covered when ANY of the following are met in a member with a DSM-5 psychiatric diagnosis:
inv-03: Covered Services and Treatment Modalities — Covered when medical necessity and staffing/supervision requirements are met:
Covered when medical necessity and staffing/supervision requirements are met:
Physician and professional time not included in the per diem is billed separately.
Services are not covered when the medical necessity criteria for admission or continued stay or the policies listed below are not followed. For Medicaid members aged 21–64, prior authorization is required; hospitals must contact the Tailored Plan/Prepaid Inpatient Health Plan (TP/PIHP) utilization review contractor for authorization within 72 working hours of an emergency admission. Failure to obtain required authorizations or to follow these policies may result in non-payment.
Services are not covered when the medical necessity criteria for admission or continued stay are not met. Additionally, procedural requirements for Medicaid admissions must be followed: if a patient applies for Medicaid during or after an inpatient psychiatric stay, the hospital must send the complete medical record to the TP/PIHP utilization review contractor or NC Medicaid utilization review contractor within the timeframes specified, and must obtain and submit the patient’s MID number; failure to comply may result in denial of reimbursement.
Service Codes and Billing Units
| 0160 | Service Code listed in document |
Authorization, Documentation, and Provider Responsibilities
Request TP/PIHP authorization within 72 working hours; observe 15‑day monthly authorization limits
Contact the Tailored Plan/Prepaid Inpatient Health Plan (TP/PIHP) utilization review contractor to request authorization within 72 working hours of admission. Initial authorizations average ~7 days; no more than 15 days may be authorized in a single calendar month for psychiatric treatment (the 15-day monthly limit may be exceeded for substance use disorder treatment). For admissions spanning two months, up to 15 days may be authorized each month (allowing up to ~30 calendar days across the two months).
- Authorization request must be submitted to the TP/PIHP within 72 working hours of admission.
- Initial authorization typically ~7 days; concurrent authorization based on medical necessity.
- Limit of 15 authorized days per calendar month for psychiatric treatment; exceptions for SUD and consecutive-month admissions described in policy.
Confirm member meets the listed preadmission clinical criteria before admission
Ensure the member meets preadmission review clinical criteria before admission: for substance use disorders, one of the listed SUD criteria (e.g., need for medical detoxification, risk of convulsions/delirium tremens, need for skilled observation, danger to self/others, or significant medical/psychiatric disorder). For non‑substance psychiatric diagnoses, one of the listed criteria must be present (e.g., impaired reality testing, danger to self/others, severe functional impairment, failure of less‑restrictive treatments, need for skilled observation or special procedures).
- SUD admission criteria include need for skilled observation or therapeutic milieu, medical detoxification not manageable by alternatives, imminent convulsions/delirium/psychosis, danger to self/others not manageable by alternatives, or significant medical/disabling psychiatric disorder.
- Non‑SUD psychiatric criteria include impaired reality testing, disordered behavior, danger to self/others, concomitant severe medical illness or SUD, severely impaired functioning not treatable by alternatives, failure of alternative treatments, or need for skilled observation/special diagnostics or therapeutic milieu.
Complete service order on or before first day and submit medical records/MID when eligibility is pending
Complete and submit required documentation per Medicaid and TP/PIHP rules: a signed service order by an authorized clinician must be completed prior to or on the first day of service, and hospitals must send the patient's medical record and obtain/submit the MID number when eligibility is pending or applied during/after the stay.
- Service order must be completed by a physician, licensed psychologist, physician's assistant, or nurse practitioner per scope of practice prior to or on the first day of service.
- If Medicaid eligibility is pending or applied during/after stay, hospitals must send the complete medical record to the TP/PIHP utilization review contractor within required timeframes and obtain/submit the MID number with the record.
Denial risk if medical necessity, prior authorization, or Medicaid submission rules are not followed
Non‑payment or denial can occur if medical necessity criteria, prior authorization, or Medicaid submission rules are not followed; hospitals must contact the TP/PIHP utilization review contractor within 72 working hours for emergency admissions or risk non‑reimbursement if MID numbers or timely records are not provided.
- Services are not covered when medical necessity criteria for admission or continued stay are not met.
- Failure to obtain required prior authorization within 72 working hours for Medicaid admissions or failure to obtain/submit the MID number and timely medical records can result in non‑payment.
Policy Background
IMD services provide 24-hour intensive evaluation and treatment for acute and subacute psychiatric and substance use disorders, delivered by nursing and medical professionals under psychiatrist supervision. The program focuses on acute symptom reduction using medication management, individual and group psychotherapy, dual diagnosis treatment, milieu treatment, medical care, and supportive services, with physician assessments within 24 hours of admission and ongoing nursing monitoring.
Key Definitions
Inpatient / IMD Level-of-Care Criteria
General Inpatient Behavioral Health Services
inv-15: General inpatient behavioral health services
Physician assessments within 24 hours of admission; psychiatrist available by phone 24 hours/day; RN assessment on admission.
Authorized Stay Limits
OpenPayer is powered by Trek Health's payer performance platform. Trek continuously ingests, validates, and normalizes Transparency in Coverage data alongside payer policies and other commercial payer data to create a structured payer intelligence foundation. OpenPayer uses this foundation to deliver personalized search results, dynamically generated policy pages, and tailored policy monitoring based on each user's payers, specialties, billing codes, and areas of interest. The same intelligence powers broader payer performance workflows, including reimbursement benchmarking, contract evaluation, payer negotiations, and financial decision-making.