Medicare gives sleep apnea patients 90 days to prove they can use a CPAP machine. If they fall short, coverage can be pulled. A new study presented at the American Thoracic Society 2026 International Conference suggests that this policy may be cutting off access to treatment for tens of thousands of patients who would have eventually benefited.
The research, led by Dennis Hwang, MD, a sleep and pulmonary physician at Kaiser Permanente Southern California, analyzed data from more than 132,000 patients treated for obstructive sleep apnea — making it one of the largest studies ever to examine real-world CPAP adherence patterns over time.
The 90-Day Cliff
Under current Medicare policy, patients must use their CPAP machine for at least four hours per night on 70% of nights during a 30-day window within the first 90 days to maintain coverage. Fail to hit that threshold, and insurers can stop paying for the device — effectively taking it away.
The Kaiser Permanente data revealed how common that failure is: 51% of patients did not meet the 90-day Medicare adherence criteria. By conventional insurance logic, these patients would be classified as treatment failures.
But the researchers tracked what happened next.
The Surprise in the Second Year
More than one-third of patients who did not meet the early Medicare threshold were still using their CPAP machine one year later. Even among those who were not hitting the four-hour mark, many were still using the device for at least two hours per night — an amount that research has shown improves symptoms of obstructive sleep apnea, including daytime sleepiness, blood pressure, and quality of life.
"While clinicians know some patients take time to adapt, the scale of continued use we observed in those that did not initially meet Medicare adherence was striking," Hwang said.
Why Early Struggles Are a Poor Predictor
CPAP therapy involves sleeping with a mask that delivers pressurized air to keep the upper airway open. For many patients, adapting to the sensation takes time. Common early complaints include mask discomfort, nasal congestion, dry mouth, air swallowing, and claustrophobia. Sleep specialists have long observed that many patients who struggle initially go on to tolerate and even prefer the therapy once they find the right mask type, pressure setting, or humidification level.
The 90-day window does not account for this adaptation curve. A patient who is gradually desensitizing to CPAP, or who is waiting for a follow-up visit to adjust their equipment, can lose coverage before they have had a genuine chance to succeed.
The American Thoracic Society issued a policy statement in 2023 arguing that the four-hour adherence threshold is arbitrary and that two hours per night may be a more appropriate minimum for determining clinical benefit. The Kaiser Permanente data adds large-scale evidence to that argument.
A Policy That May Create the Problem It Measures
There is an additional concern: the 90-day rule may itself discourage long-term use. Patients who learn early that their insurance has been denied may give up on a therapy that would have worked with more time and support. The study raises the possibility that a policy designed to identify treatment failures is, in some cases, manufacturing them.
Many private insurers follow Medicare's lead on CPAP coverage criteria, meaning the impact extends well beyond the Medicare population. Millions of commercially insured sleep apnea patients face similar early-use requirements.
What This Means for Patients
Patients who have recently been prescribed CPAP and are struggling with it should not assume they have failed. The Kaiser Permanente data suggests that adaptation is common and that many patients who do not meet early thresholds go on to use the therapy successfully.
If your insurer denies continued CPAP coverage based on the 90-day criteria, consider the following steps:
- Ask your sleep physician for a peer-to-peer review with the insurer. Clinicians can often make the case that continued coverage is warranted based on the patient's trajectory.
- Request a mask or pressure adjustment. Early nonadherence is frequently a mask-fit problem, not a therapy problem. A different mask style or the addition of heated humidification can make a significant difference.
- Document your usage. Even subthreshold use demonstrates engagement with the therapy and can support an appeal.
The study does not argue that every patient benefits from CPAP, and some patients genuinely prefer or respond better to alternative treatments such as oral appliances, positional therapy, or emerging pharmacological options. But it makes a compelling case that the current system is making a permanent judgment based on temporary data — and that thousands of patients are losing access to effective treatment as a result.
