Medicare will pay for a new CPAP machine once every five years. That five-year clock starts from the date you first begin using the equipment, and the machine must have reached what Medicare calls its “reasonable useful lifetime” before a replacement is covered. Outside of that timeline, Medicare will cover an earlier replacement only if your machine is lost, stolen, or damaged beyond repair.
How the 13-Month Rental Works
Medicare doesn’t buy you a CPAP machine outright. Instead, it pays a supplier to rent one to you over 13 continuous months. During that period, you’re responsible for 20% of the Medicare-approved rental amount each month after you’ve met your annual Part B deductible. Once all 13 monthly rental payments are complete, ownership of the machine transfers to you. At that point, the supplier is no longer involved, and the machine is yours to keep.
The key word here is “continuous.” If you stop using the machine or your coverage lapses during that 13-month window, the rental clock can reset. Consistent use matters not just for your health but for keeping the financial arrangement on track.
The Five-Year Replacement Rule
After you own the machine, Medicare considers five years to be its reasonable useful lifetime. Once that period has passed, you can qualify for a new machine, which starts another 13-month rental cycle. You’ll need a new prescription from your doctor and may need an updated sleep study, depending on how long it’s been since your last one.
If your machine breaks, gets lost, or is stolen before the five years are up, Medicare can cover a replacement. You’ll typically need documentation of what happened, such as a police report for theft or a statement from your supplier confirming the machine can’t be repaired. Normal wear and tear that a repair could fix generally won’t qualify you for a full replacement.
Qualifying for Coverage in the First Place
Before Medicare pays for any CPAP equipment, you need a qualifying diagnosis of obstructive sleep apnea based on a sleep study. The specific thresholds are based on how many breathing disruptions you have per hour of sleep, measured as your Apnea-Hypopnea Index (AHI):
- AHI of 15 or higher: You qualify with at least 30 total events recorded during the study, with no additional conditions required.
- AHI between 5 and 14: You qualify only if the study records at least 10 events and you also have documented symptoms like excessive daytime sleepiness, mood disorders, impaired cognition, or insomnia. A history of high blood pressure, heart disease, or stroke also satisfies this requirement.
Home sleep tests and in-lab polysomnography studies can both be used to establish the diagnosis. Your doctor orders the study, and the results go to Medicare along with a prescription for the CPAP.
What You’ll Pay Out of Pocket
CPAP machines fall under Medicare Part B as durable medical equipment. You pay 20% of the Medicare-approved amount for each monthly rental payment, and Medicare covers the remaining 80%. The annual Part B deductible ($257 in 2025) applies first, so your earliest payments in the year may be higher until you’ve met that threshold.
If you have a Medigap (supplemental) policy, it may cover some or all of that 20% coinsurance. Medicare Advantage plans cover CPAP equipment too, but the costs and supplier networks vary by plan. Check with your specific plan before ordering.
Supplies Have Their Own Replacement Schedule
The five-year rule applies to the machine itself, but CPAP supplies like masks, tubing, filters, and water chambers wear out much faster and have their own replacement timelines under Medicare. These are general guidelines for how often Medicare will cover replacements:
- Full face masks or nasal masks: Once every 3 months
- Mask cushions: Twice per month (full face) or once per month (nasal)
- Tubing: Once every 3 months
- Disposable filters: Twice per month
- Non-disposable filters: Once every 6 months
- Water chamber (humidifier): Once every 6 months
- Headgear and chinstraps: Once every 6 months
These supplies are also covered at 80% by Medicare after your deductible, so you’ll pay 20% of the approved amount for each item. Your supplier should be enrolled in Medicare and accept assignment, meaning they agree to charge only the Medicare-approved price.
Choosing a Supplier
You need to get your CPAP machine and supplies from a Medicare-enrolled supplier. In the past, Medicare ran a competitive bidding program that restricted which suppliers you could use in certain areas, but that program is currently in a temporary gap period as of January 2024. During this gap, you can use any Medicare-enrolled supplier, though pricing is adjusted based on previous competitive bidding rates and inflation factors.
Not every supplier accepts Medicare assignment, and those that don’t can charge you more than the approved amount. Before placing an order, confirm that the supplier is enrolled in Medicare, accepts assignment, and can verify your coverage. Many suppliers handle the paperwork and communicate directly with your doctor’s office to ensure everything is in order before shipping equipment.