Last verified 2026-08-17
Medicare and CPAP: the compliance rule nobody explains
When Medicare starts paying for your CPAP, the first 3 months are a trial period for coverage. To keep Medicare paying, you have to meet two separate requirements: attend a follow-up visit in a specific window and use the machine enough for the recorded data to meet Medicare’s adherence rule.
Put both deadlines on your calendar when the machine arrives. They are easy to miss if you assume the supplier or clinic is tracking them for you.
The machine is rented first
Medicare initially pays for CPAP as rented durable medical equipment rather than buying the machine outright. Once your diagnosis and the initial coverage requirements are established, the rental period begins.
Continued payment depends on what happens during that trial. Your equipment supplier can help with the data and paperwork, but the follow-up visit still has to happen and the machine still has to show enough use.
The follow-up visit
Your treating practitioner needs to re-evaluate you in person no earlier than day 31 and no later than day 91 after therapy begins.
At that visit, the practitioner has to document that you are benefiting from PAP and review a written report of your usage data.
This is a coverage window, not just a suggested follow-up interval. If the office moves your appointment, check the date yourself. A visit on day 30 is too early. A visit after day 91 is outside the original window.
Missing day 91 does not necessarily end coverage permanently. If a later re-evaluation documents that you used PAP and benefited from it during the trial period, continued coverage can begin again from the date of that later visit. You can still be left with an uncovered gap.
The usage requirement
Medicare defines adherence as using the device for at least 4 hours per night on 70% of nights during any consecutive 30-day period within the first 3 months.
70% of 30 nights is 21 nights. You can miss 9 nights in that 30-day stretch and still meet the rule.
The qualifying stretch does not have to be your first 30 days. If the first few weeks go badly while you are working through mask leak or another problem, you still have roughly 90 days to produce one consecutive 30-day period that meets the threshold.
The 4-hour number is Medicare’s reimbursement threshold. It is not a clinical target for how much of the night you should use PAP.
How Medicare gets the usage data
Modern PAP machines record use automatically. The data are usually transmitted by cellular or wireless connection to your equipment supplier, so you do not need to keep a paper log.
Most manufacturers also give you an app that shows the same basic usage information. Check it during the first month. If you keep landing at 3 hours and 45 minutes, you want to know that while there is still time to fix the problem, not after the qualifying window has closed.
If the numbers in the app look wrong, ask your supplier what data it is receiving. A connection problem and a true adherence problem are different issues and need different fixes.
If the usage requirement is not met
Coverage for continued rental and supplies stops. That does not create a lifetime ban on PAP.
If the initial 12-week trial fails, Medicare’s current PAP coverage determination requires an in-person clinical re-evaluation to determine why the first trial failed and a repeat facility-based Type 1 sleep study before you can requalify. The repeat study can be diagnostic, titration, or split-night.
That makes it worth addressing problems early rather than simply waiting out the trial. Common reasons for low use include mask leak, a mask design that does not fit your face or sleeping position, pressure intolerance, dry mouth or nose, and claustrophobia. Depending on the problem, the response can include refitting the mask, trying a different mask, adjusting ramp or pressure-relief settings, moving to bilevel therapy, adding humidification or heated tubing, or using a minimal-contact mask design.
→ Why your mask leaks, and what to change → Mask finder
If PAP is not working
Tell the clinician managing your therapy rather than simply stopping the machine.
That note in your chart can matter later. Coverage for an oral appliance or a surgical treatment often requires documentation that you tried PAP and either could not tolerate it or did not succeed with it. If you quietly stop, the next insurer reviewing an alternative treatment may see no record of why PAP ended.
You do not need to keep using an intolerable setup in silence just to create documentation. You do need to tell the clinician what is happening while there is still a record of the trial and the problem.
Commercial insurance
Many large commercial insurers use a similar adherence standard, but the exact timing and documentation requirements vary by plan.
Ask your equipment supplier for the rule that applies to your plan. Get the required number of hours, the measurement window, any follow-up visit requirement, and the date by which each requirement has to be met. If the supplier cannot tell you, call the insurer before the trial period is over.
The thresholds described here are Medicare’s and were verified against the current CMS PAP LCD and related Policy Article on the date shown. Other plans may use different rules. This is not medical advice. Four hours is a billing threshold, not a clinical target for how much PAP you should use.