Medicare and CPAP: Coverage Rules, Compliance, and Replacement Schedules

Older adult in bedroom wearing CPAP mask near modern CPAP machine on nightstand with Medicare card and smartphone showing usage data

Understand how Medicare covers CPAP therapy, what documentation and compliance rules you must meet, and when replacement parts are allowed. This guide explains coverage criteria, rental timelines, tracking requirements, mask and accessory replacement schedules, and practical tips to improve comfort and long-term adherence.

How Medicare Covers CPAP Therapy

Understanding how Medicare covers CPAP therapy is the first step in getting the treatment you need for Obstructive Sleep Apnea (OSA). CPAP, which stands for Continuous Positive Airway Pressure, is the most common and effective treatment for OSA. The therapy works by delivering a steady stream of pressurized air through a mask, which keeps your airway open while you sleep and prevents the repeated breathing interruptions that define the condition. Because untreated OSA is linked to serious health problems like hypertension, heart disease, and stroke, Medicare considers CPAP therapy a medical necessity for beneficiaries with a confirmed diagnosis.

Coverage for your CPAP machine and supplies falls under Medicare Part B, as they are classified as Durable Medical Equipment (DME). Your path to coverage will depend on whether you have Original Medicare or a Medicare Advantage (Part C) plan. While Medicare Advantage plans are required to provide at least the same level of coverage as Original Medicare, their specific rules often differ. For example, an Advantage plan may require you to use suppliers within their network or get prior authorization before they will cover the equipment. It is always a good idea to contact your plan administrator directly to confirm their policies for DME.

Getting a Diagnosis Medicare Will Accept

Before Medicare will pay for CPAP therapy, you must have a formal diagnosis of OSA confirmed by a sleep study. This is the cornerstone of your claim, providing the objective data Medicare requires. Medicare accepts results from two types of tests.

  • Polysomnography (PSG) This is an in-lab sleep study conducted overnight at a sleep center. Technicians monitor your brain waves, breathing, heart rate, and oxygen levels.
  • Home Sleep Apnea Test (HSAT) This is a simplified test you can do in your own bed using an FDA-cleared portable monitoring device. It records key metrics like your breathing, airflow, and blood oxygen levels.

Regardless of the test type, a qualified sleep specialist must interpret the results. To ensure the results meet Medicare’s strict criteria, the final report must be detailed and specific. It must clearly state your Apnea-Hypopnea Index (AHI) or Respiratory Disturbance Index (RDI), document periods of oxygen desaturation, and include a typed, formal interpretation from the sleep specialist, not just handwritten notes.

Meeting Medicare’s Medical Necessity Thresholds

A diagnosis alone isn’t enough; your sleep study results must meet specific criteria to prove medical necessity. Medicare uses the Apnea-Hypopnea Index (AHI), which measures the average number of breathing pauses or shallow breaths you experience per hour of sleep. According to the Centers for Medicare & Medicaid Services (CMS) National Coverage Determination, coverage is granted if you meet one of these two conditions.

  • Your AHI is 15 or greater.
  • Your AHI is between 5 and 14, and you have documented symptoms of certain comorbidities. These include conditions like excessive daytime sleepiness, hypertension, ischemic heart disease, or a history of stroke.

For clinicians, documentation is critical in cases where a patient’s AHI falls between 5 and 14. Your notes must explicitly connect the sleep apnea diagnosis to symptoms like excessive daytime sleepiness, impaired cognition, or mood disorders. A note simply stating “patient is tired” won’t suffice. Instead, something like, “Patient reports significant daytime hypersomnolence impacting daily activities, co-managed for hypertension (ICD-10 code I10),” provides the necessary clinical context.

The Rental Process and What You’ll Pay

Medicare covers CPAP equipment through a rental-to-own model. You will not own the machine from day one. Instead, Medicare helps pay for a 13-month rental period. This begins with a three-month trial period to ensure the therapy is working for you. If you meet the compliance rules during this trial, Medicare will continue to cover its portion for the remaining 10 months. After 13 months of continuous use and rental payments, the machine is yours.

Financially, you are responsible for your annual Part B deductible, which is $240 for 2024. Once that is met, Medicare pays 80% of the Medicare-approved amount for the monthly rental fee. You pay the remaining 20% coinsurance. It is critical that both your ordering physician and your DME supplier are enrolled in Medicare and accept assignment. If they are not, you could be responsible for the entire cost. It is also important to note that Medicare will not reimburse you for a CPAP machine you purchase directly; you must use a Medicare-enrolled DME supplier who handles the billing through the rental-to-own program.

Assembling the Essential Documentation

Proper documentation is the key to getting your CPAP therapy approved. Your medical record must contain clear evidence supporting the need for treatment, and a missing item can bring the entire process to a halt. Your DME supplier will need the following from your doctor.

  • A Signed Physician Order: This is the formal prescription for your CPAP machine and supplies. It must be signed and dated by your treating physician. An unsigned order is one of the most common and easily avoidable reasons for denial.
  • The Sleep Study Report: The full, official report showing your AHI and other relevant data, including a formal interpretation from a sleep specialist.
  • Clinical Notes: Chart notes from your face-to-face evaluation that document your OSA diagnosis, discuss your symptoms, and formally prescribe the therapy.
  • CMN or DMEPOS Forms: Depending on your Medicare Administrative Contractor (MAC), you may need a Certificate of Medical Necessity (CMN) or a DME Information Form (DIF). Your DME supplier typically initiates this form, which your doctor completes to certify that the CPAP therapy is medically necessary.

Avoiding Common Pitfalls for a Smooth Approval

A denied claim is frustrating, but many are preventable. The most frequent reasons for denial include insufficient documentation, a missing physician signature, or working with a DME supplier who is not enrolled in Medicare. You can take several proactive steps to minimize these risks.

First, if you have a Medicare Advantage plan, always check for preauthorization requirements. Many of these plans require prior approval before they will cover a sleep study or CPAP device. Second, confirm that your chosen DME supplier is enrolled and participates in Medicare. You can verify this using Medicare’s supplier directory. Finally, ensure all documentation is submitted together as a complete packet. From your sleep test to the day your device arrives, you should generally expect the process to take two to four weeks.

If you receive a denial, you have the right to appeal. The first level is a “Redetermination,” which must be filed within 120 days of the denial notice. To build a strong case, include a copy of the denial letter, a detailed letter from your doctor explaining why CPAP is medically necessary, your full sleep study report, and your recent compliance data.

Patient Checklist for Your Doctor’s Appointment

Bring this checklist to your appointment to help ensure you cover all the bases for a smooth approval process.

  • Confirm my sleep study report includes my AHI/RDI score, oxygen desaturation levels, and a typed interpretation.
  • If my AHI is between 5 and 14, have we documented my related symptoms (like daytime sleepiness, high blood pressure, or heart conditions) in my medical record?
  • Do I have a signed and dated physician’s order (prescription) for CPAP therapy?
  • Has my chosen DME supplier been confirmed as an enrolled, participating Medicare provider?
  • If I have a Medicare Advantage plan, have we completed any required preauthorization?
  • Can you provide me with a copy of all submitted documentation for my records?

Compliance Monitoring and Ongoing Coverage

Once your new CPAP machine is delivered, Medicare’s coverage enters a critical trial phase. This isn’t just about getting used to the therapy; it’s about proving to Medicare that it’s effective for you. Continued coverage for both the machine rental and your future supplies hinges on meeting specific usage requirements during the first three months.

The most important rule to understand is the compliance threshold. To continue coverage beyond the initial trial, you must demonstrate that you are using the CPAP device for at least four hours per night on 70% of the nights during any consecutive 30-day period within the first 90 days of therapy. This is the standard Medicare uses to determine if you are benefiting from the treatment. Your durable medical equipment (DME) supplier is responsible for documenting this usage and reporting it.

Fortunately, you don’t have to keep a manual log. Modern CPAP machines are equipped with internal modems or data cards that record objective usage data automatically. This includes how many hours you used the machine each night, your mask leak rate, and your residual Apnea-Hypopnea Index (AHI). This data is transmitted wirelessly to your supplier through a cloud-based system or downloaded from a data card during a follow-up visit. This objective report is the primary evidence submitted to Medicare to prove compliance.

Medicare covers your CPAP machine under a 13-month capped rental agreement. If you successfully meet the compliance requirements during your initial 90-day trial, Medicare will continue to pay its 80% share of the monthly rental fee. After 13 consecutive months of rental payments, ownership of the machine transfers to you. If you fail to meet compliance, Medicare will stop paying for the rental, and your supplier may be required to take the machine back. You can find more details on the initial trial period on the official Medicare website here.

What Happens if You Struggle with Compliance?
It’s common to have trouble adjusting to CPAP therapy, so don’t panic if your initial usage is low. The goal is to identify and solve the problem. If you’re not meeting the 4-hour threshold, the first step is to contact your DME supplier or sleep doctor immediately. Common issues include:

  • Mask Fit and Comfort. An ill-fitting mask that leaks or causes discomfort is the number one reason people stop using their CPAP. Your supplier can schedule a mask refitting session to help you try different styles or sizes.
  • Pressure Settings. The air pressure might feel too high or too low. Your doctor may need to adjust the settings or order a titration study to find the optimal pressure for you.
  • Dryness or Congestion. A lack of humidity can cause a dry mouth or nasal passages. Adjusting your humidifier settings or using heated tubing can make a significant difference.

Follow-up visits are built into the process to help you succeed. A crucial appointment must occur between the 31st and 91st day of your therapy. During this visit, your doctor will review your usage data, discuss your progress, and document in your medical record that the therapy is helping. This physician’s note, along with the machine’s compliance report, is the key documentation submitted to Medicare. Telehealth check-ins are often used for these follow-ups, making them more convenient.

Documentation and Medicare Advantage Plans
The compliance report your supplier generates is a simple summary. It typically lists the date range, the total number of nights the device was used, the number of nights it was used for more than four hours, and the resulting compliance percentage. For example, a report might show “Usage over 30 days: 25 of 30 nights > 4 hours (83% compliance).” This is the proof Medicare needs.

If you have a Medicare Advantage (Part C) plan, the rules can differ. While these plans must provide at least the same level of coverage as Original Medicare, their methods for tracking compliance and their documentation requirements may vary. Many Medicare Advantage plans require preauthorization for CPAP therapy and may have their own specific forms or data submission portals. It is essential to contact your plan provider directly to understand their exact compliance and reporting procedures to avoid any surprises or gaps in coverage.

Replacement Schedules for Masks, Accessories, and Machines

Once you’ve met Medicare’s compliance requirements, the next step is maintaining your therapy for the long haul. A huge part of that is regularly replacing your CPAP supplies. Using worn-out equipment can lead to mask leaks, skin irritation, and poor therapy, which puts your health and your Medicare coverage at risk. Think of it like changing the oil in your car; it’s routine maintenance that prevents bigger problems down the road.

Medicare covers the replacement of your CPAP supplies on a set schedule because components wear down with use. Here are the generally accepted replacement timelines you can expect.

  • Mask Cushions and Nasal Pillows. These parts have the most direct contact with your skin and oils, causing them to break down quickly. Medicare typically covers up to two replacement nasal pillows (or pairs of pillows) or one full-face mask cushion per month.
  • Full Masks (including frame). A complete mask system, including the frame but not the headgear, is typically covered every 3 months.
  • Headgear. The straps that hold your mask in place lose elasticity over time, which can force you to overtighten the mask and cause discomfort. Medicare generally authorizes a new one every 6 months.
  • Tubing or Hose. Over time, small tears or holes can develop in the tubing, reducing air pressure. It’s also a place where moisture can collect. Plan on replacing it every 3 months.
  • Filters. These are your machine’s first line of defense against dust and allergens. Medicare covers up to two disposable filters per month or one non-disposable, washable filter every six months.
  • Humidifier Water Chamber. Mineral deposits from water can build up and crack the chamber over time. Medicare usually covers a replacement every 6 months.

Your DME supplier typically bundles these items into your ongoing supply orders. After you meet your annual Part B deductible, Medicare pays 80% of the approved amount for these supplies, and you are responsible for the remaining 20%. Most suppliers have an automated system to remind you when you’re eligible for new supplies, but it’s smart to track it yourself. If a part breaks or wears out ahead of schedule, contact your supplier. They will likely need a new prescription from your doctor explaining why an early replacement is medically necessary.

Choosing the right replacement parts can make a world of difference. If your current mask causes red marks or leaks, talk to your supplier about alternatives. For example, memory foam cushions can offer a gentler seal than silicone. Getting the size right is also critical; many manufacturers offer printable sizing guides online. Proper cleaning also extends the life of your supplies. Wiping your mask cushion daily and washing your mask, headgear, and tubing weekly in warm, soapy water can keep them in good shape between replacements.

Eventually, your CPAP machine itself will need to be replaced. Medicare recognizes that these devices have a limited lifespan and will typically cover a new machine every five years. A replacement may be authorized sooner if your machine malfunctions and cannot be repaired, is lost or stolen, or if your doctor determines that your therapeutic needs have changed. To get a replacement, your doctor will need to provide new documentation to your DME supplier confirming that you continue to use and benefit from the therapy, along with a prescription for the new device.

Closing Summary and Next Steps

Navigating the path to consistent, Medicare-covered CPAP therapy can feel complex, but by understanding the core principles, you can confidently manage your treatment. This guide has walked you through the essential details, from initial diagnosis to long-term equipment management. Let’s synthesize the most critical takeaways to ensure you have a clear roadmap for success.

At its heart, Medicare’s approach is straightforward. It will cover CPAP therapy, which it classifies as Durable Medical Equipment (DME), when there is clear, documented medical necessity. This begins with a qualifying sleep study—either an in-lab polysomnography (PSG) or an approved home sleep apnea test (HSAT)—that confirms a diagnosis of Obstructive Sleep Apnea (OSA) based on specific Apnea-Hypopnea Index (AHI) thresholds. Your physician’s clinical evaluation and detailed notes are the foundation upon which your entire coverage rests.

The second pillar of coverage is compliance. Medicare invests in your therapy with the expectation that you will use it. For the initial three-month trial period, you must demonstrate adherence. The rule is firm: use your device for at least four hours per night on 70% of nights within any consecutive 30-day period. Modern CPAP machines track this data automatically, and your supplier is responsible for reporting it. Meeting this benchmark is non-negotiable for Medicare to continue paying for the device rental and subsequent supplies.

Finally, the system relies on a partnership between you, your clinician, and your DME supplier. Each has a role in providing the necessary documentation, from the initial prescription and sleep study interpretation to the follow-up evaluation between the 31st and 91st day of therapy that confirms you are benefiting from the treatment. Similarly, Medicare has established a standard replacement schedule for your supplies, like masks, cushions, tubing, and filters. Clear communication with your supplier is essential to stay on track with replacements.

With these key points in mind, here is a prioritized checklist to guide your next steps and ensure a smooth experience.

  1. Confirm Your Diagnosis and Documentation is Compliant.
    Before anything else, review your sleep study results with your doctor. Ensure your AHI meets Medicare’s criteria and that your medical record thoroughly documents your diagnosis and the symptoms that make CPAP therapy medically necessary. This paperwork is the key that unlocks coverage.
  2. Choose a Medicare-Participating DME Supplier.
    It is crucial to select a supplier that is enrolled in Medicare and “accepts assignment.” This means they agree to accept the Medicare-approved amount as full payment and will not bill you for more than the standard 20% coinsurance and any unmet deductible. This single step protects you from unexpected and potentially large bills.
  3. Schedule a Thorough Mask Fitting.
    Do not underestimate the importance of a comfortable mask. An ill-fitting mask is the most common reason people fail to meet compliance. Work closely with your supplier’s respiratory therapist to try different styles (nasal, pillows, full face) and sizes. A proper fit prevents leaks, reduces skin irritation, and makes it significantly easier to wear the device for the required four hours.
  4. Activate Data Sharing and Schedule Your Follow-Up.
    When you receive your CPAP machine, confirm with your supplier that the internal modem is active and transmitting your usage data. This is how compliance is proven. At the same time, schedule your follow-up appointment with your sleep clinician. This visit must occur between day 31 and day 91 of starting therapy to secure long-term coverage. Mark this window on your calendar.
  5. Maintain Detailed Records.
    Keep a dedicated folder for all your CPAP-related paperwork. This includes a copy of your sleep study, the physician’s prescription, your agreement with the DME supplier, and any Explanations of Benefits (EOB) you receive from Medicare. If you ever face a coverage denial, this organized documentation will be your most powerful tool for a successful appeal.

Policies can evolve, so it’s always wise to be proactive. We encourage you to periodically check for updates from the Centers for Medicare & Medicaid Services (CMS) or, more specifically, the Local Coverage Determinations (LCDs) published by the Medicare Administrative Contractor (MAC) for your region. If you have a Medicare Advantage plan, consult your plan’s specific evidence of coverage documents, as their rules for pre-authorization and preferred suppliers may differ. Your most valuable resources remain your sleep clinician and your DME supplier; never hesitate to ask them for clarification.

By actively managing your therapy and understanding the rules, you are doing more than just navigating a system. You are making a direct investment in your own well-being, ensuring restful nights and better health for years to come.

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Legal Disclaimers & Brand Notices

General Medical Disclaimer: The information provided in this article is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition, procedure, or treatment plan, especially concerning Obstructive Sleep Apnea (OSA) and CPAP therapy.

Regulatory and Coverage Notice: Information regarding Medicare coverage, compliance requirements, AHI thresholds, and replacement schedules is based on current Centers for Medicare & Medicaid Services (CMS) National Coverage Determinations (NCDs) and standard Local Coverage Determinations (LCDs). Medicare policies, deductibles, and co-insurance rates are subject to change. Readers should always confirm specific coverage details, including preauthorization requirements, directly with their Medicare Administrative Contractor (MAC) or Medicare Advantage plan administrator.

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