Bilevel (often called BiPAP) and adaptive servo-ventilation (ASV) are prescribed for specific conditions, and Medicare’s rules depend on which condition you have. This guide summarizes the two CMS policies: LCD L33718 for obstructive sleep apnea and LCD L33800, Respiratory Assist Devices for everything else. It isn’t a substitute for your supplier’s or practitioner’s reading of the policy.
The codes
| HCPCS | Device | Covered for OSA? |
|---|---|---|
| E0601 | CPAP (including auto-CPAP) | Yes, when criteria are met |
| E0470 | Bilevel without backup rate | Only after E0601 tried and proven ineffective (L33718) |
| E0471 | Bilevel with backup rate | No (L33718) |
Obstructive sleep apnea: CPAP first
Under L33718, Medicare covers E0470 for OSA only after CPAP has been tried and proven ineffective. This matches the AASM’s 2019 guidance, which suggests CPAP or APAP over bilevel for routine OSA (AASM 2019). See APAP vs CPAP vs BiPAP and the Medicare CPAP guide.
Other conditions: LCD L33800
L33800 (latest revision listed as effective 9 June 2025) covers E0470 and E0471 for restrictive thoracic disorders, central sleep apnea (CSA) or complex sleep apnea (CompSA), hypoventilation syndrome, and chronic respiratory failure consequent to COPD.
| Condition | Key initial criteria (summary of L33800) | Device |
|---|---|---|
| Restrictive thoracic disorders (neuromuscular disease such as ALS, or severe thoracic cage abnormality) | Documented diagnosis; and awake PaCO₂ ≥ 45 mm Hg, or sleep oximetry SpO₂ ≤ 88% for ≥ 5 minutes (2-hour minimum recording), or for neuromuscular disease only, maximal inspiratory pressure under 60 cmH₂O or FVC under 50% predicted; and COPD doesn’t contribute significantly | E0470 or E0471 (practitioner’s choice) |
| Central or complex sleep apnea | Complete facility-based, attended PSG documenting CSA/CompSA and significant improvement on the home settings, on your prescribed oxygen | E0470 or E0471 (practitioner’s choice) |
| Hypoventilation syndrome | Awake PaCO₂ ≥ 45 mm Hg and FEV1/FVC ≥ 70%, plus either PaCO₂ worsening ≥ 7 mm Hg during or right after sleep, or SpO₂ ≤ 88% for ≥ 5 minutes not caused by obstructive events (AHI under 5) | E0470 first; E0471 only with further criteria while on E0470 |
| Chronic respiratory failure from COPD | Separate criteria in L33800 | See the LCD |
Source: CMS LCD L33800, read 13 October 2026. If the criteria aren’t met, the LCD says the device and accessories will be denied as not reasonable and necessary.
Months 1–3, then the 61-day re-evaluation
For restrictive thoracic disorders, CSA/CompSA and hypoventilation, coverage starts with the first three months. To continue, L33800 requires:
- A re-evaluation by the treating practitioner no sooner than 61 days after starting therapy.
- Documentation of how symptoms are progressing and how you’re using the device.
- Use averaging 4 hours per 24 hours by the time of the re-evaluation. Less is treated as non-compliant use and is reason to deny continued coverage.
- A signed, dated practitioner statement, made no sooner than 61 days in, that you’re using the device compliantly and benefiting.
Medicare won’t pay for month 4 onward until this is done.
ASV: who it is and isn’t for
ASV is prescribed for central sleep apnea patterns. The safety warnings matter:
- ResMed’s AirCurve 10 ASV user guide says ASV therapy is contraindicated in patients with chronic, symptomatic heart failure (NYHA 2–4) with reduced left ventricular ejection fraction (LVEF ≤ 45%) and moderate to severe predominant central sleep apnea.
- The AASM’s updated recommendation says ASV targeted to normalize AHI should not be used for CHF-related central sleep apnea in adults with LVEF ≤ 45% and moderate or severe CSA-predominant sleep-disordered breathing, because of evidence of an increased risk of death. It can be used with LVEF above 45% or mild CHF-related CSA (AASM ASV update).
- The AASM’s safety notice advises assessing every patient for heart failure before ASV, and measuring LVEF objectively if symptoms are present (AASM safety notice).
The AirCurve 10 ASV guide lists a maximum supplemental oxygen flow of 15 L/min in CPAP and ASV modes and 4 L/min in ASVAuto (AirCurve 10 ASV user guide). See CPAP with oxygen.
Checklist before you order
| Step | Why |
|---|---|
| Confirm the diagnosis code and condition category | Decides which LCD applies |
| Make sure the required test is done (PSG, ABG, oximetry, spirometry) | The criteria are test-based |
| Ask whether E0470 or E0471 is being ordered and why | E0471 isn’t covered for OSA |
| Diary the 61-day re-evaluation | Coverage for month 4 onward depends on it |
| Use the device at least 4 hours a night on average | Below that counts as non-compliant |
| For ASV: get an LVEF assessment if you have heart failure symptoms | Contraindication and AASM guidance |
Verdict
For obstructive sleep apnea, Medicare wants CPAP tried first, and bilevel with a backup rate isn’t covered. For other conditions, the criteria are test-driven, with a 61-day check before month 4. ASV can help some central sleep apnea patients, but it must not be used in symptomatic heart failure with LVEF ≤ 45%. Make sure that’s been checked.
Related: Medicare home oxygen coverage, HSA/FSA eligibility, AirSense 11 vs AirSense 10.
Device review: ResMed AirCurve 11 VAuto.