Sleep apnea is one of the most commonly service-connected conditions among veterans, and one of the most frequently misunderstood when it comes to ratings, evidence, and secondary claims. This article explains what sleep apnea is, why it develops in veterans, how the VA rates it, what evidence strengthens a claim, how it connects to other service-connected disabilities, and what to do if a claim is denied.

What Is Sleep Apnea

Sleep apnea is a disorder in which breathing repeatedly stops and starts during sleep. The most common form among veterans is obstructive sleep apnea (OSA), where the airway collapses or becomes blocked during sleep, cutting off airflow for seconds at a time, sometimes dozens or hundreds of times per night. Each pause in breathing drops blood oxygen levels and briefly wakes the brain, even when the veteran does not fully remember waking up.

Less common forms include central sleep apnea, where the brain fails to send proper signals to the muscles that control breathing, and mixed sleep apnea, which combines both mechanisms. All forms are diagnosed through the same testing process and rated under the same VA criteria, though the underlying cause matters for establishing service connection and for a treating physician’s nexus opinion.

Severity is measured using the Apnea-Hypopnea Index (AHI), which counts the average number of breathing pauses per hour of sleep. Five to fifteen events per hour is generally classified as mild, fifteen to thirty as moderate, and more than thirty as severe. It is important for veterans to understand that this clinical severity scale does not map directly onto the VA disability rating scale, which is discussed further below.

Why Veterans Develop Sleep Apnea During or After Service

Sleep apnea in veterans is often connected to conditions common in military service. Weight gain following separation, driven by reduced physical activity and dietary changes, is one of the most frequent contributing factors, since excess weight around the neck and airway increases the likelihood of airway collapse during sleep. Chronic sinus and nasal conditions from environmental and occupational exposures, deviated septum or airway trauma from training or combat injuries, and sleeping in awkward positions or environments during deployment can also contribute to airway changes over time.

One of the strongest and most medically documented connections is between sleep apnea and PTSD. Research has repeatedly shown that veterans with PTSD have significantly higher rates of sleep apnea than the general population, likely due to changes in muscle tone, breathing regulation, and sleep architecture caused by chronic hyperarousal. This connection is significant because it allows many veterans to file sleep apnea as secondary to an already service-connected mental health condition rather than needing to prove a direct in-service event.

Many veterans do not notice symptoms, or do not connect their symptoms to a medical condition, until years after separation. A spouse or partner may be the first to notice loud snoring or witnessed breathing pauses. This delayed recognition is common and does not by itself weaken a claim, but it does make it more important to build a clear evidentiary chain connecting current symptoms back to service or to another already-rated condition.

How the VA Rates Sleep Apnea

Sleep apnea is rated under 38 CFR 4.97, Diagnostic Code 6847, using four possible levels.

0 percent is assigned when a veteran has a documented sleep disorder confirmed by a sleep study, but the condition does not currently require treatment.

30 percent is assigned when the veteran experiences persistent daytime hypersomnolence, meaning excessive daytime sleepiness that continues even with treatment attempts, or in cases where treatment has not yet been established.

50 percent is assigned when the veteran requires the use of a breathing assistance device, most commonly a CPAP (continuous positive airway pressure) machine, though BiPAP and oral appliance devices can also qualify depending on the specific medical circumstances.

100 percent is assigned in the most severe cases, where the veteran has developed chronic respiratory failure with carbon dioxide retention, cor pulmonale (right-sided heart failure caused by lung or breathing problems), or requires a tracheostomy.

This structure surprises many veterans because it does not scale with the AHI severity of the underlying sleep study. A veteran with a mild diagnosis who is prescribed a CPAP machine is rated at 50 percent, the same level as a veteran with a severe diagnosis who also uses a CPAP machine, because the rating criteria are based on functional treatment need rather than raw test results. This is why simply having a diagnosis, without documentation of prescribed treatment, often results in a lower rating than expected.

Evidence That Strengthens a Sleep Apnea Claim

A current diagnosis. A sleep study, typically an in-lab polysomnogram or an at-home sleep apnea test, is required to establish that the veteran currently has a diagnosed sleep disorder. Without this, the VA has no clinical basis to rate the condition regardless of symptoms.

An in-service event or a documented secondary connection. For direct service connection, this can include documented complaints of snoring, witnessed breathing pauses noted by a bunkmate, unit member, or spouse during service, treatment for a related condition such as chronic sinusitis or a deviated septum, or separation exam notes referencing fatigue or sleep complaints. For secondary claims, this instead requires medical evidence linking the sleep apnea to an already service-connected condition such as PTSD, weight-limiting orthopedic injuries, or certain respiratory conditions.

A medical nexus opinion. Because sleep apnea is frequently diagnosed years after separation, a written nexus opinion from a treating physician or an independent medical examiner is often the single most important piece of evidence in the claim. The strongest nexus letters use the specific phrase that the condition is “at least as likely as not” related to service or to an existing service-connected condition, since this phrasing directly matches the legal standard VA raters apply.

Proof of CPAP compliance. For veterans seeking the 50 percent rating, the VA specifically wants evidence that a breathing device was prescribed and is actually being used. CPAP data download reports showing hours of nightly use, durable medical equipment prescription records, and physician follow-up notes discussing compliance and effectiveness all support this element of the claim.

Sleep Apnea as a Secondary Condition

Sleep apnea is one of the more frequently approved secondary conditions in VA disability claims, largely because the medical literature supporting these connections is well established. Veterans already rated for PTSD or another mental health condition, or veterans with orthopedic disabilities such as knee, back, or hip conditions that significantly limit exercise and contribute to weight gain, often have a strong medical basis for filing sleep apnea secondary to those conditions.

A secondary claim requires the same three elements as a direct claim, except the in-service event is replaced with medical evidence that the already service-connected condition caused or aggravated the sleep apnea. This typically means a nexus opinion that explicitly explains the physiological mechanism, for example how chronic PTSD-related hyperarousal disrupts breathing regulation during sleep, or how a service-connected knee injury led to reduced activity, weight gain, and subsequent airway narrowing.

Common Reasons Sleep Apnea Claims Are Denied

The most frequent reason sleep apnea claims are denied is a missing or weak nexus opinion connecting the current diagnosis to service or to a secondary condition. A close second is a sleep study performed long after separation or long after the C&P exam, without any explanation in the record for the delay between symptom onset and diagnosis. Generic, templated nexus letters that do not reference the veteran’s specific service history, deployment conditions, or existing medical records are also a common reason for denial, since VA raters are trained to give these boilerplate opinions less weight than individualized assessments.

Veterans who receive a denial should carefully review the rating decision to identify exactly which of the three required elements, current diagnosis, in-service event or secondary link, and nexus opinion, the VA found insufficient, since this determines whether a supplemental claim with new evidence or a formal appeal is the more appropriate next step.

Filing Tips for Veterans

Keep copies of every sleep study, CPAP prescription, and equipment supply record, since these documents are frequently requested again during future rating increases, reevaluations, or reviews. When requesting a nexus opinion, provide the treating physician with a clear written timeline of relevant events, including when a primary condition such as PTSD began, when weight gain or symptom onset occurred, and when the sleep apnea diagnosis followed, so the opinion can address the specific chain of causation rather than speaking in general terms. During any C&P exam, be specific and consistent about symptoms, including how often breathing pauses are witnessed, how many hours of CPAP use occur nightly, and how daytime sleepiness affects work, driving, and daily functioning, since examiners rely heavily on the veteran’s own description of functional impact.

Conclusion

Sleep apnea is a serious and highly compensable condition for veterans, but the difference between a 0 percent, 30 percent, and 50 percent rating often comes down to specific pieces of evidence rather than the severity of the underlying sleep disorder itself. Veterans pursuing a direct or secondary sleep apnea claim should focus on securing a clear diagnosis, a strong and individualized nexus opinion, and documented proof of prescribed treatment to support the highest accurate rating for their condition.