What documentation is required for Continuous Positive Airway Pressure (CPAP) therapy in patients with obstructive sleep apnea?

Documentation Required for CPAP Usage

For Medicare and most insurance reimbursement, you must document: (1) objective polysomnography confirming OSA diagnosis with specific AHI thresholds, (2) face-to-face clinical reevaluation between days 31-91 showing symptom improvement, and (3) objective adherence data demonstrating CPAP use ≥4 hours/night on 70% of nights during any consecutive 30-day period within the first 3 months. 1

Initial Diagnostic Documentation

Polysomnography (PSG) is mandatory for CPAP reimbursement by CMS and most insurers. 1 The diagnostic sleep study must include:

• Comprehensive PSG measurements: oxygen saturation, rib cage and abdominal movement, nasal and oral airflow, snoring sounds, electroencephalography, electrooculography, electromyography, electrocardiogram, and leg electromyogram to document periodic leg movements 1
• Apnea-Hypopnea Index (AHI) documentation: CMS covers treatment when AHI >15, or when AHI >5 with comorbidities such as excessive daytime sleepiness, hypertension, or cardiovascular disease 1
• CPAP titration data: PSG is typically followed by continuous positive airway pressure titration to determine therapeutic pressure 1

Important caveat: If CPAP was initially prescribed based on portable monitoring and the patient subsequently fails the 90-day adherence criteria, CMS mandates an in-laboratory polysomnogram, though the validity of this requirement is questionable in patients with unequivocal severe OSA on portable studies 1

Pre-Treatment Clinical Documentation

Document the following clinical elements in the medical record:

• Cardinal OSA symptoms: excessive daytime sleepiness (EDS), snoring, witnessed apneas, nocturia, cognitive impairment 1
• Epworth Sleepiness Scale (ESS): useful for documenting baseline daytime drowsiness, though not validated in older adults 1
• Physical examination findings: upper airway assessment (nasal and pharyngeal), skeletal facial structure (retrognathia/micrognathia), neck collar size (>17 inches in men, >16 inches in women), obesity assessment 1
• Comorbidities: hypertension (especially treatment-resistant), heart disease, hypothyroidism, stroke, diabetes 1
• Medication review: sedative-hypnotics, opiate analgesics, alcohol use—all can contribute to breathing difficulties or daytime sleepiness 1

Adherence Monitoring Documentation (Days 31-91)

CMS requires specific adherence documentation between Day 31 and Day 91 after initiating therapy for continued reimbursement beyond 12 weeks. 1 This includes:

Objective CPAP Usage Data

Download and document from the CPAP device's tracking system:

• Total nights CPAP was used vs. not used 1
• Percentage of nights with usage >4 hours/night 1
• Average usage on nights when CPAP was used 1
• Average usage on all nights 1

The adherence threshold: CPAP use ≥4 hours/night on 70% of nights during any consecutive 30-day period within the first 3 months 1

Face-to-Face Clinical Reevaluation

The treating physician must conduct and document a face-to-face visit (not just review of downloaded data) showing: 1

• Symptom improvement: documented reduction in OSA symptoms such as daytime sleepiness (ESS), nocturia, headaches, sleep fragmentation, or insomnia 1
• Quality of life improvement: using validated instruments like FOSQ, SF-36, or SAQLI 1
• Comorbidity improvement: blood pressure reduction, improved diabetic control, reduced cardiovascular symptoms 1

Additional Technical Parameters to Document

While not always required for basic reimbursement, document these parameters to demonstrate therapeutic effectiveness:

• Residual AHI on CPAP: event detection from device tracking systems 1
• Mask leak data: excessive leak compromises effectiveness; thresholds vary by manufacturer (ResMed: >24 L/min nasal, >36 L/min full-face; Fisher & Paykel: >60 L/min; DeVilbiss: >95 L/min) 1, 2
• Pressure settings: document therapeutic pressure level 1

Critical Timing Considerations

The American Thoracic Society recommends earlier adherence assessment (7-90 days rather than waiting until day 31) because addressing CPAP intolerance early improves long-term adherence. 1 However, CMS reimbursement rules mandate the 31-91 day window for formal documentation. 1

Early follow-up within 2 weeks of CPAP initiation is recommended by the American Academy of Sleep Medicine to optimize adherence, though this is separate from the formal CMS documentation requirement. 3

Common Documentation Pitfalls

• Waiting too long to address problems: CPAP adherence patterns are typically established early in treatment; delaying intervention until day 31 may allow problems to become entrenched 1
• Relying solely on objective data without clinical assessment: CMS requires both objective adherence data AND documented clinical benefit from a face-to-face evaluation 1
• Missing the 31-91 day window: documentation outside this timeframe may not satisfy CMS requirements for continued coverage 1
• Inadequate baseline symptom documentation: without clear baseline symptoms documented, demonstrating improvement becomes difficult 1

Ongoing Long-Term Documentation

OSA should be treated as a chronic disease requiring longitudinal monitoring. 1 Continue documenting:

• Periodic adherence downloads: monitor CPAP usage long-term, not just during the initial 90 days 1
• Clinical outcomes: ongoing assessment of symptoms, comorbidities, and quality of life 1
• Side effects and interventions: document mask discomfort, nasal symptoms, pressure intolerance, and management strategies 3, 4