Medical Necessity & Concurrent Review in Behavioral Health (ASAM Explained)

Medical necessity is the gatekeeper of behavioral health revenue. A payer can deny an entire episode of care — clinically appropriate or not — if the documentation doesn’t establish that the treatment was medically necessary at the level it was delivered. Understanding how medical necessity and concurrent review work is essential to getting paid.

Key takeaway: In behavioral health, getting paid is less about the diagnosis and more about whether your documentation answers three questions for every authorized period: why this level of care, why now, and why continued.

This article is part of our behavioral health revenue cycle management guide.

What “medical necessity” actually means to a payer

Medical necessity is the standard a payer uses to decide whether it will cover a service. For behavioral health, payers evaluate whether the level of care matches the patient’s clinical acuity — not just whether the patient has a covered diagnosis. A patient may genuinely need residential treatment, but if the record doesn’t show the acuity that justifies residential over IOP, the claim is exposed.

ASAM criteria: the common benchmark

For substance use treatment, most commercial payers anchor medical-necessity decisions to ASAM criteria, which assess the patient across six dimensions:

1. Acute intoxication / withdrawal potential
2. Biomedical conditions and complications
3. Emotional, behavioral, or cognitive conditions
4. Readiness to change
5. Relapse / continued-use potential
6. Recovery / living environment

Strong documentation maps the patient’s presentation to these dimensions and connects them to the level of care billed. This is the backbone of both clean billing and successful appeals.

Concurrent review: where days get lost

Initial authorization is only the beginning. Payers require concurrent review (also called continued-stay review) — periodic re-justification that the patient still needs the current level of care. Each payer sets its own interval and format.

This is one of the most expensive failure points in behavioral health RCM. A concurrent review that’s late, incomplete, or missing can turn a week of legitimate, delivered care into unbillable days. Tracking review due-dates and never missing one is, in dollar terms, one of the highest-ROI activities in the revenue cycle.

How to document so payers keep paying

A few habits dramatically reduce medical-necessity denials:

• Write to the criteria. If the payer uses ASAM, structure notes so a reviewer can find each dimension quickly.
• Show change over time. Document response to treatment and the clinical reasoning for continued stay.
• Be specific. “Patient is doing well” doesn’t justify continued residential care; specific, observable clinical detail does.
• Synchronize auth with care. When a patient steps up or down a level of care, the authorization must move with them.

Connecting documentation to revenue

Medical-necessity documentation isn’t a compliance chore — it’s a revenue function. It determines whether claims are paid, whether appeals succeed, and whether concurrent days are reimbursed.

This is also a natural fit for AI and automation: models can flag thin documentation before submission and surface upcoming concurrent-review due dates so none slip. Pair that with disciplined denial management and the right KPIs, and medical-necessity denials drop sharply.

To see how much your facility is losing to medical-necessity and concurrent-review issues, book a revenue audit.

Frequently asked questions

What are ASAM criteria?

ASAM criteria are the American Society of Addiction Medicine's standards for placing, continuing, and transitioning patients across levels of addiction care. They assess the patient across six dimensions — from withdrawal risk to recovery environment — and most commercial payers use them as the benchmark for medical-necessity decisions in substance use treatment.

What is concurrent review in behavioral health?

Concurrent review (or continued-stay review) is the ongoing utilization-review process where a payer re-evaluates whether continued treatment at a given level of care remains medically necessary. Facilities must submit clinical updates at payer-defined intervals; a missed or late concurrent review can render otherwise-billable days unpayable.

How do you prove medical necessity for behavioral health treatment?

You prove medical necessity by documenting the patient's clinical presentation against the payer's accepted criteria (often ASAM), showing active treatment and response, and providing continued-stay justification at each review. Documentation should clearly answer why this level of care, why now, and why continued care is required.