Access to Inpatient Substance Use Disorder Treatment Under RCW 48.43.761 — Technical Assistance Advisory
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Guidance to health carriers on interpretation and implementation of RCW 48.43.761 regarding prior authorization and coverage for initial inpatient, residential, and withdrawal management substance use disorder treatment in Washington state.
No material clinical or coverage changes in this revision.
Coverage and Authorization Rules
inv-01: Initial coverage and voluntary prior authorization rules
Covered without required prior authorization when the following statutory timeframes apply:
Once the statutory period elapses, utilization review may be conducted consistent with RCW 48.43.761(2).
A voluntary prior authorization must address the period subsequent to the statutory initial period and must be supported by clinical material demonstrating medical necessity for the requested days.
Applies to admissions resulting from voluntary prior authorization requests and other admissions where no prior determination was made.
Protection applies where authorization has been granted for a specified length of stay.
inv-02: Medical necessity standard
Medical necessity and level-of-care determinations must use:
Health plans and providers are encouraged to collaborate on the documentation needed to demonstrate medical necessity for the requested level of care.
RCW 48.43.761 does not obligate carriers to provide a voluntary prior authorization option. Carriers may elect to accept voluntary prior authorization requests initiated by the enrollee or their substance use disorder treatment provider prior to admission, but the statute does not require carriers to offer that option.
If a carrier has authorized a particular length of stay, the carrier may not shorten the approved length of stay on the basis that it is no longer "medically necessary" under RCW 48.43.761(2)(c)(iii). This protection applies when an authorization has been granted for a defined length of stay.
Provider Notifications, Voluntary Authorization, and Documentation
Voluntary prior authorization allowed
Carriers may accept voluntary prior authorization requests initiated by the enrollee or provider prior to admission; any voluntary prior authorization must specify coverage for the period after the statutory initial period (two business days for inpatient/residential or three days for withdrawal management).
- Voluntary prior authorization for inpatient/residential must address the period subsequent to the two business day statutory period.
- Voluntary prior authorization for withdrawal management must address the period subsequent to the three day statutory period.
Submit assessment, treatment plan, and admission notice
Include an initial assessment and initial treatment plan when seeking voluntary prior authorization; the admitting behavioral health organization must notify the health plan of the admission within 24 hours.
- Submit clinical material that supports medical necessity for the level of care requested when requesting voluntary prior authorization.
- Admitting behavioral health organization must provide notice of admission to the health plan within 24 hours.
Documentation must support medical necessity (use ASAM)
When using voluntary prior authorization, clinical material from the referring provider must demonstrate medical necessity for the level of care requested; an initial assessment and initial treatment plan submitted for prior authorization satisfies the related statutory requirements.
- Clinical material must support the number of days and level of care being pre-authorized.
- ASAM criteria must be incorporated into the patient assessment and support the treatment plan for services covered by RCW 48.43.761.
Denial does not bar later admission if ASAM criteria met
A voluntary prior authorization request may be denied; if it is denied and the client's condition later changes to meet ASAM criteria, the provider may admit the client based on their assessment of medical necessity.
- If no medical necessity determination is made prior to admission, carriers may pend the review but must pay for services delivered from time of admission until the written decision is provided.
- An authorization once granted cannot be shortened later on the grounds it is no longer medically necessary.
Statutory Background and Purpose
RCW 48.43.761 establishes that health plans may not require prior authorization for an initial short period of substance use disorder treatment: three days for withdrawal management and two business days (excluding weekends and holidays) for inpatient or residential treatment. The advisory clarifies that these minimum timeframes also apply when an admission results from an approved voluntary prior authorization—voluntary authorizations must address the period subsequent to the statutory initial days.
When voluntary prior authorization is used, submission of an initial assessment and initial treatment plan with the prior authorization request satisfies the related statutory requirements for documentation, and the admitting behavioral health organization must notify the health plan of admission within 24 hours. If no medical necessity determination is made before admission, carriers may pend the review but must pay for services delivered from the time of admission until a written decision is provided.
Standards and Definitions
Criteria for Inpatient, Residential, and Withdrawal Management
Modalities Covered and Application
inv-12: Inpatient, Residential, Withdrawal Management
Applies to inpatient, residential, and withdrawal management modalities; voluntary prior authorization must specify coverage for days after the statutory initial period.
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