← Back to HCPCS Code Library
What this equipment is
E0470 is the HCPCS code for a bilevel positive airway pressure device with a backup rate (BiPAP ST or BiPAP ASV). Unlike CPAP, which delivers one continuous pressure, BiPAP delivers two levels — a higher pressure on inhale (IPAP) and a lower pressure on exhale (EPAP). The backup rate forces a breath if the patient doesn't trigger one within a set time.
BiPAP is used for complex sleep-disordered breathing, CPAP-intolerant patients, COPD with overlapping OSA, and central sleep apnea. It's a step up from CPAP — both clinically and in payer scrutiny.
Medicare coverage criteria
- Failed CPAP trial. Most payers require documentation that CPAP was tried and failed or was not tolerated before approving BiPAP. "Failed" typically means adherence <4 hours/night despite adequate support.
- Central or mixed sleep apnea. BiPAP ST (spontaneous-timed) or ASV (adaptive servo-ventilation) is used for central sleep apnea (G47.31) or complex sleep apnea. The sleep study must demonstrate central or mixed events, not purely obstructive.
- Documented CPAP intolerance. Physical intolerance (claustrophobia, mask pressure sores), side effects (aerophagia), or documented inability to tolerate CPAP at therapeutic pressure.
- COPD with nocturnal hypoventilation. Some payers cover E0470 for COPD patients with documented nocturnal hypercapnia (elevated PaCO2) or oxygen saturation drops below 88% despite CPAP.
What actually causes denials in DME back offices
- No CPAP failure documentation. The most common denial reason for E0470 is a missing or inadequate CPAP trial record. Payers want evidence CPAP was attempted — compliance data from the device download is the gold standard.
- Wrong sleep study type. An in-lab attended PSG is preferred for BiPAP authorization; home sleep tests may not be sufficient for complex sleep diagnoses. Confirm payer requirements before the study.
- Missing sleep physician interpretation. The sleep study report must include a physician's interpretation with event counts (AHI, central apnea index, mixed events) — not just raw data from the device.
- Diagnosis mismatch. Billing E0470 for pure obstructive sleep apnea (G47.33) with no evidence of central or complex apnea often triggers denial. BiPAP is not simply "stronger CPAP" — the clinical rationale must match the diagnosis.
- No PA number. E0470 is frequently a PA-required code for commercial payers. The PA must reflect the correct device type (BiPAP ST vs. ASV) — using a generic PA for "BiPAP" may not authorize the specific E0470 device.
Documentation checklist
- Physician order specifying BiPAP ST or ASV with backup rate settings
- Sleep study report with central/mixed apnea indices and physician interpretation
- CPAP trial data showing failure or intolerance (device download report)
- Documented reason CPAP was inadequate — not just "patient preference"
- CMN with qualifying diagnosis and length of need
- PA number from payer
Reimbursement note: E0470 rental rates are slightly higher than E0601 due to the more complex device. Medicare allows approximately 15–20% more for E0470 than E0601 depending on region. Commercial payer contracts vary — verify your allowed amount before billing. ASV devices (E0471) are a separate, more expensive code with stricter coverage criteria.
Book a Demo
See how ScriptRelay automates verification, intake, and denial management for DME distributors.
Book a 20-Min Walkthrough →
Frequently asked questions
Do I need to try CPAP before billing E0470?
Most payers — including Medicare Advantage plans — require a documented CPAP trial with evidence of failure or intolerance before approving E0470. The device download showing poor adherence (<4 hrs, <70% nights) is the strongest proof. "Patient tried CPAP" without documentation will not satisfy most payers.
What is the difference between BiPAP ST and BiPAP ASV?
BiPAP ST (spontaneous-timed) delivers pressure support on patient-triggered breaths and applies a set minimum rate if the patient doesn’t breathe. BiPAP ASV (adaptive servo-ventilation) continuously adjusts pressures breath-by-breath and is specifically used for central sleep apnea. E0470 covers ST; ASV devices may fall under different codes with separate coverage criteria.
Can I upgrade a patient from CPAP to BiPAP mid-rental?
Yes, with documentation. Submit a new order for E0470 with the CPAP failure documentation, device compliance report, and updated CMN. The existing E0601 rental should be stopped on the date the new device is delivered. Some payers will authorize the upgrade during the CPAP rental period; others require you to complete the CPAP rental first.