Multiple Sleep Latency Test (MSLT) and Maintenance of Wakefulness Test (MWT) — CPB 0330 | AETNA Coverage Update

TL;DR: Aetna modified CPB 0330 for the Multiple Sleep Latency Test (MSLT) and Maintenance of Wakefulness Test (MWT), effective September 26, 2025. Here's what billing teams need to act on now.

Aetna, a CVS Health company, updated its Aetna MSLT and MWT coverage policy under CPB 0330 Aetna system, narrowing the covered indications to two specific diagnostic scenarios and setting strict limits on repeat testing. CPT 95805 is the primary code at stake. If your sleep center or neurology practice bills Aetna for MSLT or MWT services, this policy defines exactly when you get paid — and when you don't.

Quick-Reference Table

Aetna MSLT and MWT Coverage Criteria and Medical Necessity Requirements 2025

The Aetna MSLT and MWT coverage policy is tight. Two indications qualify for medical necessity coverage under CPB 0330. Everything else is a denial waiting to happen.

Aetna covers CPT 95805 — multiple sleep latency or maintenance of wakefulness testing, recording, analysis, and interpretation — when the test is used to evaluate symptoms of narcolepsy and confirm the diagnosis. That's indication one. Indication two: evaluating patients with suspected idiopathic hypersomnia to differentiate it from narcolepsy. Both are ICD-10 territory you'll find in the G47.4xx and G47.1x code ranges.

That second indication matters. Idiopathic hypersomnia (G47.10–G47.19) is on the covered list, but only when the clinical question is whether the patient has hypersomnia or narcolepsy. Billing for hypersomnia evaluation alone — without that differential diagnosis framing — is a different clinical situation. Your documentation needs to reflect the diagnostic question being answered.

The medical necessity standard here is narrower than what some billing teams assume. A patient with excessive daytime sleepiness, general fatigue, or a suspected circadian disorder doesn't automatically qualify. The policy requires a clear path toward either a narcolepsy confirmation or an idiopathic hypersomnia-versus-narcolepsy workup. If your physician's order and clinical notes don't show that, you're exposed.

Prior authorization requirements aren't explicitly called out in this policy update, but that doesn't mean you skip it. Aetna routinely requires prior auth for sleep studies under this CPB. Verify auth requirements by plan type before you schedule the test — not after you bill it.

Aetna MSLT and MWT Repeat Testing: When It's Covered and When It Isn't

Repeat MSLT and MWT testing is not medically necessary by default. Aetna is explicit about that. If a patient already had a test, you need a documented reason that falls into one of three specific exceptions.

Exception one: the initial test was invalid or uninterpretable. Exception two: extraneous circumstances affected the initial test, or study conditions weren't met during the initial session. Exception three: the patient is suspected to have narcolepsy, but the earlier MSLT or MWT didn't produce polygraphic confirmation.

That third exception is the one most billing teams will use. Narcolepsy without polygraphic confirmation — meaning the test didn't capture the clinical findings needed to confirm the diagnosis — is a legitimate repeat indication. But your documentation has to carry the argument. The prior test results, the reason for inconclusiveness, and the clinical rationale for repeating must all be in the record.

If a repeat test doesn't fit one of these three boxes, Aetna considers it not medically necessary. Billing it anyway means a claim denial and potential recoupment exposure. Talk to your compliance officer before billing repeat studies if the documentation is thin.

Coverage Indications at a Glance

Aetna MSLT and MWT Billing Guidelines and Action Items 2025

The effective date is September 26, 2025. Here's what to do before and after that date.

CPT, HCPCS, and ICD-10 Codes for MSLT and MWT Under CPB 0330

Covered CPT Codes (When Selection Criteria Are Met)

Key ICD-10-CM Diagnosis Codes

The full ICD-10 list in CPB 0330 runs 99 codes. That's a broad diagnostic universe, but remember: code presence on the list doesn't equal automatic MSLT/MWT reimbursement. Coverage still hinges on the two clinical indications.

The dementia, Parkinson's, and ADHD codes on this list reflect the broader clinical context in which sleep disorders appear — not expanded indications for MSLT/MWT coverage. Don't use a dementia or ADHD diagnosis as your primary claim driver for CPT 95805. The covered indication still has to be narcolepsy evaluation or the hypersomnia-versus-narcolepsy differential.