Medicare CPAP Compliance Requirements Explained

Updated September 2026. Written by Matteo Grassi, clinical psychologist and cofounder of HANA Health.

Medicare CPAP compliance is the two part test a patient must pass to keep PAP coverage after the first three months. The patient must use the device at least 4 hours a night on 70% of nights during one consecutive 30 day period, and the treating practitioner must see them in person between day 31 and day 91 to document benefit. Miss either, and coverage stops, under LCD L33718 as of 2026.

From the clinical side, I've always found it striking that a whole coverage decision rests on how a patient feels about a mask in their first few weeks.

Key facts

• Usage threshold: PAP use of 4 or more hours a night on 70% of nights in a consecutive 30 day period, anytime in the first 3 months. (LCD L33718)
• Re-evaluation window: an in person clinical re-evaluation no sooner than day 31 and no later than day 91 after therapy starts. (LCD L33718)
• Trial length: Medicare initially covers CPAP for a 12 week period to identify patients who benefit. (NCD 240.4)
• Claims: from month 4 onward, the supplier may add the KX modifier only when both initial and continued coverage criteria are met. (Policy Article A52467)
• Error rate: CPAP had a 12.5% improper payment rate in the 2024 reporting period, about $146.1 million, and insufficient documentation caused 71.2% of PAP improper payments. (CMS MLN)
• Real world adherence: only 48% of 213,341 commercially insured patients met the CMS standard in all four quarters of year one. (Alpert et al., CHEST 2024)

What counts as CPAP compliance for Medicare?

Compliance means use of the PAP device for 4 or more hours a night on at least 70% of nights during a consecutive 30 day period, anytime in the first three months of use. That's the definition in LCD L33718, the local coverage determination all four DME MACs apply.

In practice, 70% of 30 nights is 21 nights. The patient doesn't need 90 perfect nights. They need one clean 30 day stretch, and it can start on day 1 or day 60, as long as it ends inside the first three months.

Three details trip people up:

• It's objective data only. The patient's own account doesn't count. The policy article says adherence is shown by direct download or visual inspection of the device's usage data, written up in a report.
• Four hours means four hours. A night of 3 hours 50 minutes doesn't count toward the 21.
• The same rule covers E0601 and E0470. The LCD uses "PAP device" for both the CPAP (E0601) and the bilevel device without backup rate (E0470) when it treats obstructive sleep apnea.

The usage threshold is only half the test. The other half is the visit.

What must the face to face re-evaluation between day 31 and 91 show?

The treating practitioner must see the patient in person, no sooner than day 31 and no later than day 91 after therapy starts, and document two things: that the patient's sleep apnea symptoms have improved, and that the practitioner reviewed objective evidence of adherence.

Both parts matter. A note that says "doing well on CPAP" without symptom detail, or a download that sits in the supplier's files but never reaches the practitioner's chart, can fail review.

The policy article adds a point suppliers often miss. Forms that a supplier creates and asks the practitioner to fill in are not a substitute for the practitioner's own medical record. The record itself has to carry the evidence.

What if the visit happens late? If the re-evaluation happens after day 91 but shows benefit and adherence, coverage resumes from the date of that visit. The months in between aren't covered. That gap is a real loss for the supplier and it comes purely from scheduling, not from the patient's therapy.

What happens if a patient fails the 90 day trial?

If a patient doesn't meet both criteria, continued coverage of the device and its accessories is denied as not reasonable and necessary. Masks, cushions, tubing and filters go with it, because accessories are covered only when the device criteria are met.

The patient can requalify, but the bar is higher the second time. The LCD requires both of these:

1. An in person clinical re-evaluation by the treating practitioner to work out why therapy failed.
2. A repeat sleep test in a facility based setting (a Type I study). It can be a diagnostic, titration or split night study.

A home test won't do for the retry. That means a lab booking, a wait and another round of paperwork. Fixing a mask leak or a pressure problem in week three is far easier than starting over in month five.

The LCD also expects the supplier to find out if a patient stops using the device at any point, and to stop billing for the equipment and supplies.

How does compliance affect supplier billing and the 13 month rental?

Compliance decides whether months 4 through 13 get paid. Under the policy article, claims for months 1 to 3 carry the KX modifier when initial coverage criteria are met. From the fourth month on, the KX modifier goes on only if the continued coverage criteria are also met.

Suppliers have two options when documentation isn't back in time:

• Submit without KX. The claim goes in, but without the modifier expect it to be denied.
• Hold the claims. Wait for the practitioner's documentation, then submit with KX. If the visit happened after day 91, only dates of service after that visit can carry KX.

The policy article describes Medicare paying for the base device over 13 months of continuous use. After that, replacement accessories need documentation that the device still meets a medical need and that the replacement is needed.

Step by step: a compliance checklist for the first 91 days

Here's a simple sequence built from the LCD and policy article requirements. Days are counted from the start of therapy.

1. Before delivery. Confirm the standard written order, the qualifying sleep test and the in person evaluation before the sleep test are on file.
2. Day 0. Instruct the patient or caregiver in use and care of the equipment, and document it. This is a coverage criterion, not a courtesy.
3. Days 1 to 14. Check usage data early. Low nights usually point to mask fit, leak, dryness or pressure, and those are fixable.
4. Day 30 or so. Check whether a qualifying 30 day window already exists. If not, work out how many compliant nights are still possible before day 90.
5. Day 31 onward. The re-evaluation can happen now. Aim for a slot in the middle of the window so a missed appointment can still be rebooked before day 91.
6. Before the visit. Send the practitioner a written usage report, so the note can say it was reviewed.
7. By day 91. Confirm the note documents symptom improvement and the adherence review, then decide whether month 4 claims go out with KX.

Why do so many patients miss the threshold?

Because the early weeks are hard and the window is short. Adherence is a behaviour, and it forms or fails fast.

The evidence is sobering. In the Tele-OSA trial of 556 patients prescribed CPAP, 53.5% of the usual care group met the Medicare adherence definition at 90 days. With telemonitoring plus automated feedback and education, it was 73.2% (Hwang et al., AJRCCM 2018). Education alone didn't significantly improve adherence. Feedback tied to actual usage did.

It's worth being honest about limits. That was one trial, in one health system, over 90 days. It doesn't tell us that any outreach program will produce the same gain, and passing at day 90 doesn't guarantee a patient keeps going. In the commercial data above, fewer than half met the standard in every quarter of year one.

What this means for your DME

The compliance test is really a scheduling and documentation test wrapped around a behaviour change. The DMEs that do well treat day 91 as a deadline that starts on delivery day.

Practical next steps:

• Track each new patient's best 30 day window, not just last night's usage.
• Book the re-evaluation early in the 31 to 91 window and confirm it the week before.
• Make sure the usage report lands in the practitioner's chart, not just your system.
• Separate the patients who need a mask or pressure fix from those who need encouragement. They need different calls.
• Keep refill outreach compliant: the LCD says refill contact can't happen more than 30 days before the current supply is expected to end, and needs a documented yes from the patient.

If you use automated calls for any of this, read our explainer on AI voice calls and the TCPA healthcare exemption first. HANA builds adherence and resupply follow up for sleep teams; you can see how it works on the HANA Sleep page, and our whitepapers cover workflow design in more depth.

Frequently asked questions

Does the 30 day compliance window have to be the first 30 days?

No. It can be any consecutive 30 day period within the first three months of use. A rough first week doesn't sink the trial if a clean 30 day stretch follows before the three months end.

Can the face to face re-evaluation be done before day 31?

No. The LCD says the re-evaluation must happen no sooner than day 31. A visit before that doesn't satisfy the continued coverage requirement, so a second visit inside the window would be needed.

Do patients who already had CPAP before joining Medicare need to repeat the trial?

Not usually. For patients who got their device before fee for service Medicare, the LCD requires a qualifying prior sleep test and an in person evaluation after enrollment showing OSA and continued use. There's no requirement for a new re-evaluation of adherence in that case.

Does switching from CPAP to a bilevel device reset the 90 day clock?

It depends on timing. If the switch happens during the initial trial with more than 30 days left, the original deadlines stand. If fewer than 30 days remain, the re-evaluation and adherence documentation must happen before day 120 after the CPAP started.

Is Medicare CPAP compliance the same as commercial payer compliance?

Not necessarily. Commercial plans set their own adherence rules, and the thresholds, timelines and later checks vary by plan. Check each payer's current policy rather than assuming the Medicare rule applies.

Sources

1. CGS Administrators and Noridian Healthcare Solutions (DME MACs). LCD L33718: Positive Airway Pressure (PAP) Devices for the Treatment of Obstructive Sleep Apnea. Revision effective 1 January 2024.
2. DME MACs. Policy Article A52467: PAP Devices for the Treatment of Obstructive Sleep Apnea. Current version.
3. Centers for Medicare & Medicaid Services. NCD 240.4: Continuous Positive Airway Pressure Therapy for Obstructive Sleep Apnea. 2008.
4. Centers for Medicare & Medicaid Services, Medicare Learning Network. Continuous Positive Airway Pressure Devices and Accessories. 2024 reporting period data.
5. Hwang D, et al. Effect of Telemedicine Education and Telemonitoring on CPAP Adherence: The Tele-OSA Randomized Trial. American Journal of Respiratory and Critical Care Medicine, 2018.
6. Alpert N, et al. Performance of Claims-Based Algorithms for Adherence to PAP Therapy in Commercially Insured Patients With OSA. CHEST, 2024.

This article is educational and isn't billing, coding, clinical or legal advice. Check current CMS guidance and your MAC before you bill. If you'd like to talk through your adherence workflow, book a call with Matteo.