Continuous Positive Airway Pressure (CPAP) Therapy For Obstructive Sleep Apnea (OSA) — NCD 226 | CMS Coverage Update

TL;DR: The Centers for Medicare & Medicaid Services modified NCD 226, the National Coverage Determination governing Medicare CPAP coverage for obstructive sleep apnea, with a policy update effective March 7, 2026. Here's what billing teams need to know before submitting claims.

CMS updated NCD 226 to reflect current criteria for CPAP therapy reimbursement under Medicare's DME benefit category. The policy does not list specific HCPCS codes in this version, but it directly governs claim approval for CPAP devices and associated sleep testing — which means your documentation requirements, AHI thresholds, and 12-week trial rules are all in play. If your practice or DME supplier bills Medicare for CPAP therapy, this is the coverage policy that determines whether you get paid or get denied.

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Quick-Reference Table

Field	Detail Copy
Payer	CMS (Centers for Medicare & Medicaid Services)
Policy	Continuous Positive Airway Pressure (CPAP) Therapy for Obstructive Sleep Apnea (OSA)
Policy Code	NCD 226
Change Type	Modified
Effective Date	March 7, 2026
Impact Level	High
Specialties Affected	Sleep medicine, pulmonology, DME suppliers, primary care (ordering physicians), respiratory therapy
Key Action	Audit your CPAP intake documentation against the AHI/RDI thresholds and 12-week trial requirements before submitting new claims under this version

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CMS CPAP Coverage Criteria and Medical Necessity Requirements 2026

The core coverage policy under NCD 226 has been in place since March 13, 2008, but this 2026 modification makes it the controlling version for claims going forward. Before any Medicare reimbursement for CPAP therapy, three things must exist in the record: a clinical evaluation, a qualifying sleep test, and documented AHI or RDI findings that meet the threshold criteria.

The AHI and RDI thresholds are where most claim denials originate, and NCD 226 is precise about this. CMS covers an initial 12-week CPAP trial when the patient meets either of these medical necessity criteria:

#	Covered Indication Copy
1	AHI or RDI ≥ 15 events per hour, regardless of other symptoms, or
2	AHI or RDI ≥ 5 and ≤ 14 events per hour, with documented evidence of at least one of the following: excessive daytime sleepiness, impaired cognition, mood disorders, insomnia, hypertension, ischemic heart disease, or history of stroke.

Both of those thresholds require the AHI or RDI to be calculated on a per-hour average. If the sleep study recorded less than two hours of continuous sleep, the recorded event count must still meet the minimum that would have applied in a two-hour window. That's a documentation trap that catches DME suppliers and ordering physicians alike — if the study is short, the math has to hold up.

Hypopnea is defined here as an abnormal respiratory event lasting at least 10 seconds with at least a 30% reduction in thoracoabdominal movement or airflow from baseline, plus at least a 4% oxygen desaturation. If your sleep lab or the ordering physician is using a looser hypopnea definition — some use 3% desaturation — that discrepancy can put your AHI calculation outside Medicare's qualifying criteria. Confirm your lab's scoring methodology aligns with NCD 226 before the claim goes out.

Sleep Test Types CMS Accepts

CMS accepts four types of diagnostic studies for OSA diagnosis under this coverage policy:

The sleep test must be ordered by the treating physician prior to the study and furnished under appropriate physician supervision. "Ordered by the treating physician" is not a formality — if the ordering and treating physicians are different providers, document that relationship clearly. Missing that link is a prior authorization and claim denial risk.

The 12-Week Trial and Continued Coverage

Coverage does not automatically extend past the initial 12-week period. CPAP is subsequently covered only for patients who demonstrate benefit during that trial. CMS expects evidence of benefit — which practically means your documentation needs to show the patient used the device and responded to therapy before continued reimbursement is approved.

Benefit during the trial period is evaluated by the treating physician. If the patient doesn't demonstrate benefit, continued CPAP coverage under Medicare stops. If your DME supplier has already dispensed equipment expecting long-term coverage without this checkback built into the workflow, you have a reimbursement exposure problem.

Beneficiary Education Requirement

NCD 226 includes an explicit requirement that the CPAP provider — meaning the DME supplier — must conduct beneficiary education on proper device use before the device is dispensed. A caregiver, such as a family member who is consistently present in the home and able to operate the device safely, may fulfill this role as a compensatory measure if the beneficiary cannot.

This education requirement is not just clinical — it's a billing condition. If a claim is audited and there's no documentation that education occurred before device use began, the claim is vulnerable. Build education documentation into your intake workflow and keep it in the patient file, not just in the clinical notes.

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CMS CPAP Exclusions and Non-Covered Indications

NCD 226 sets coverage in the affirmative, but the exclusions are real. Coverage is withheld in these situations:

The non-responder exclusion is operationally significant. Once a patient completes the 12-week trial without documented benefit, Medicare won't cover ongoing CPAP rental or supplies. Make sure your billing team knows to flag those cases before claims go out, not after the denial comes back.

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Coverage Indications at a Glance

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CMS CPAP Billing Guidelines and Action Items 2026

Copy Action Items

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CPT, HCPCS, and ICD-10 Codes for CPAP Therapy Under NCD 226

NCD 226 as published in this version does not list specific CPT, HCPCS Level II, or ICD-10-CM codes within the policy document itself. This is not unusual for a National Coverage Determination — NCDs define coverage criteria and medical necessity standards, while the associated billing codes are typically specified in the Local Coverage Determinations (LCDs) and related billing and coding articles published by your MAC (Medicare Administrative Contractor).

To identify the exact HCPCS codes for CPAP devices, related accessories, and sleep study services that fall under NCD 226 in your jurisdiction, pull the corresponding LCD and billing article from your MAC's website. The HCPCS codes most commonly associated with CPAP billing under Medicare include device codes in the E-code range, but you should confirm the active code list with your MAC directly — do not rely on carryover assumptions from previous years.

If your billing team is uncertain which codes are active under this policy version as of March 7, 2026, contact your MAC or loop in your billing consultant before submitting new claims.

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