Free CPAP tool
Medicare CPAP Compliance Calculator
Medicare keeps paying for a CPAP after the trial only if you used it at least 4 hours a night on 70% of nights in a consecutive 30-day period during the first 3 months. Enter how many nights in your current window reached 4 hours and how many nights are left, and see whether you are on track.
Formula
Required nights = 70% of the window, rounded up: 30 x 0.70 = 21 nights. Share so far = qualifying nights / window x 100. You meet the rule when qualifying nights reach the required number. More nights needed = required minus what you have, never below zero. It is still possible if qualifying nights plus nights left in the window reach the requirement.
The rule comes from Medicare's PAP device coverage policy (LCD L33718): adherence is use of 4 hours or more per night on 70% of nights during a consecutive 30-day period any time in the first 3 months of use. A night counts only if it reaches 4 hours; 3 hours 50 minutes does not.
Worked example
18 qualifying nights so far, a 30-day window, 5 nights left. Required = ceil(30 x 70 / 100) = 21. Share so far = 18 / 30 x 100 = 60%. Meets now = 0 (18 is less than 21). Still needed = 21 minus 18 = 3 nights. Still possible = 1, because 18 + 5 = 23, which is at least 21.
Assumptions and limits
- Applies to Original Medicare; private plans and Medicare Advantage plans set their own rules.
- Any consecutive 30-day period in the first 3 months can be used, so a missed window can be followed by a better one.
- Your supplier's download from the machine is what counts, not your own log.
- If you fail the 12-week trial, Medicare requires an in-person re-evaluation and a repeat facility sleep test to re-qualify.
Supplies that can help
A soft strap that supports the jaw to help keep the mouth closed, used mainly with nasal and nasal pillow masks to reduce mouth leaks.
Soft fabric liners that sit between your skin and the mask cushion to reduce skin irritation, red marks and the noisy leaks some people get from …
A pillow with cutouts or a contoured edge so a mask and hose are not pushed out of place when you sleep on your side.
Tubing with a built-in heating wire that keeps humidified air warm all the way to the mask, which is the main fix for rainout (water droplets …
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Frequently asked questions
How many nights do I need to use CPAP for Medicare?
At least 4 hours on 70% of nights in a consecutive 30-day period, which is 21 of 30 nights. It has to happen in the first 3 months of use. Your clinician also has to document in a visit between day 31 and day 91 that the therapy is helping.
Does a nap count toward CPAP compliance?
Machines record usage time, and many count sessions on the same sleep day together, but the rule is about nights reaching 4 hours. Check with your supplier how your machine groups sessions. Do not rely on short naps to reach 4 hours.
What happens if I do not meet the Medicare 70% rule?
Medicare can stop paying for the rental after the trial. To re-qualify you need an in-person re-evaluation and a repeat sleep test in a facility. If masks or side effects are stopping you, tell your clinician early; mask refits often fix it.
Can I reach compliance if I missed several nights?
Yes if enough nights remain. The calculator's last output shows whether the nights left in your window can still get you to 21. If not, a new 30-day window inside the first 3 months can still qualify.
Sources
Last reviewed October 11, 2026. How we research · Report an error