Last verified 2026-08-15

Medicare and CPAP: the compliance rule nobody explains

You were given a machine. Nobody sat you down and explained that Medicare is watching how much you use it, that there’s a specific number you have to hit, that there’s a clinic visit you have to attend inside a specific window, or that missing either means the machine goes back.

Here is the whole thing in plain terms.

The machine is rented first

Medicare doesn’t buy you a CPAP outright. It rents it, and the initial rental period is covered once the diagnosis is established.

To keep paying past that initial period, two things have to happen. Both are on you and your clinician, not on the supplier.

Requirement one: the visit

You need an in-person re-evaluation with your treating practitioner, no sooner than day 31 and no later than day 91 after starting therapy.

At that visit, the practitioner has to document two things: that you’re benefiting from the therapy, and that they’ve reviewed a written report of your usage data.

This visit is the requirement most people don’t know exists. It isn’t a routine check-up you can reschedule casually — the window is fixed and the clock started when you got the machine.

If you miss the window, it isn’t automatically over. If the re-evaluation happens after day 91 and shows you used and benefited from the therapy during the trial period, continued coverage can start from the date of that later re-evaluation. You lose the gap, not the machine.

Requirement two: the usage number

Medicare defines adherence as:

Use of at least 4 hours per night, on 70% of nights, during any consecutive 30-day period within the first three months.

Three things worth pulling out of that sentence:

70% of 30 nights is 21 nights. You can miss 9 nights in the window and still qualify.

It’s any consecutive 30-day period in the first three months, not the first 30 days. A rough first month doesn’t sink you — you have roughly 90 days to produce one good 30-day stretch.

Four hours is a floor, not a goal. It’s the reimbursement threshold. It is not a statement about how much use is clinically worthwhile.

How they know

Modern machines record it themselves and transmit it, usually over cellular or wireless, to your equipment supplier. There’s nothing for you to log and no form to fill in.

It also means you can see the same numbers they’re seeing. Most manufacturers offer an app showing nightly usage. Look at it during your first month rather than finding out at the visit that you’re short. If you’re at 3 hours 45 minutes most nights, that’s a fixable problem with weeks left to fix it.

If you don’t meet it

Coverage for continued rental and supplies stops. That’s the practical consequence — not a lifetime ban.

In most cases this is a pause. The path back is to identify why you weren’t using it, address that, and re-attempt. A new adherence trial may be required.

And the reasons are usually equipment problems with equipment answers:

• Mask leak — most often over-tightened headgear or a worn cushion, not a broken therapy
• Wrong mask type — a mask that seals across your chin will fight a beard; a bulky one will fight side sleeping
• Pressure intolerance — ramp settings, pressure relief, or a bilevel machine
• Dry mouth or nose — humidification, heated tubing
• Claustrophobia — minimal-contact designs exist specifically for this

→ Why your mask leaks, and what to change → Mask finder

The thing to do if it isn’t working

Tell your clinician it isn’t working. Do not simply stop.

This matters beyond the machine. Coverage for the alternatives — an oral appliance, a surgical option — very often requires documented failure or intolerance of PAP therapy. If you quietly stop using it, there’s no record, and the next treatment becomes harder to get approved.

A recorded conversation about why PAP isn’t working for you is what keeps your other options open. Stopping without one closes them.

Commercial plans

Most large commercial insurers use a similar standard, some more permissive and some stricter, with their own documentation requirements. Your supplier verifies your specific plan’s rules, and it’s a fair question to ask them directly: what exactly does my plan require, and by when?

Thresholds described here are Medicare’s, verified against the current CMS coverage determination for PAP devices on the date shown. Your plan’s rules may differ. This is not medical advice — how much you should be using your machine is a question for the clinician managing your therapy, and four hours is a billing threshold rather than a clinical target.