By Courtesy of:
April 15, 2008

david-kuhlmann"An overnight sleep study records more signals and detects more problems than a typical home test."(DAVID KUHLMANN)

David Kuhlmann, MD, is medical director of sleep medicine at Bothwell Regional Health Center in Sedalia, Mo., and is certified in sleep medicine and neurology.

Q: How long is the wait for a sleep study?

A: Wait times vary. Some sleep disorders centers are accredited by the American Academy of Sleep Medicine (AASM). At these centers the average wait time for an overnight sleep study is about two weeks. The wait time for a home sleep test may be shorter.

Q: What are type I, type II, type III, and type IV sleep studies?

A: A type I sleep study is an overnight sleep study at a sleep disorders center. It detects obstructive sleep apnea (OSA) and many other sleep disorders. It gathers signals of all the vital signs that are related to your sleep. Each of these signals is recorded on its own "channel." Sleep disorders centers that are accredited by the AASM must record at least 12 channels of information during a sleep study.

Type II, type III, and type IV sleep studies are home sleep tests that detect OSA. A type II home sleep test records seven or more channels of information. A type III home sleep test records four to seven channels of information. This is the most common type of home sleep test. A type IV home sleep test records only one or two channels of information. The AASM does not support the clinical use of type IV home sleep tests.

Q: Is a sleep study at a sleep center better than a home sleep test?

A: Both an overnight sleep study at a sleep disorders center and a home sleep test can detect obstructive sleep apnea (OSA). But an overnight sleep study records more signals and detects more problems than a typical home sleep test. It can detect many other sleep disorders in addition to OSA. It is "attended" by a trained sleep technologist. He or she monitors your equipment to ensure that it functions properly during the night. An overnight sleep study provides your doctor with the most detailed information about your sleep.

A typical home sleep test does not record the signals needed to detect sleep disorders other than OSA. It also may be less effective if you have another medical problem or sleep disorder that affects your sleep. A home sleep test is "unattended." It is performed at home without the supervision of a health-care professional. Data loss can occur if the equipment malfunctions or is set up improperly. In both cases you may be unaware of the problem or unable to correct it. This can cause the results of the home sleep test to be inaccurate.

Q: Can I do a home sleep test on my own?

A: A home sleep test needs to be ordered by a licensed doctor. This should occur only after a full clinical evaluation indicates that you are at risk for obstructive sleep apnea (OSA). The doctor also should oversee your treatment if the home sleep test confirms that you have OSA. Board-certified sleep specialists have expertise and the most experience at evaluating people for OSA. To meet with a board-certified sleep specialist, schedule an appointment at a sleep disorders center that is accredited by the AASM.

Q: Why should I go to an accredited sleep center for a sleep study?

A: AASM accreditation is the gold standard by which you can evaluate a sleep center. Accreditation ensures that a sleep center provides the highest quality of medical care for people with sleep problems. In AASM-accredited sleep centers, the results of a sleep study are always reviewed by a board-certified sleep specialist.

Q: How do I find an accredited sleep center?

A: All the centers listed in a searchable directory at have earned accreditation from the AASM.

Q: Does Medicare cover sleep studies?

A: Yes. Medicare covers sleep studies that are performed at sleep disorders centers. Other requirements vary by region of the country.

Q: Does Medicare cover home sleep tests?

A: Yes. In March 2008 Medicare expanded its coverage to include home sleep tests. Restrictions may vary by region of the country.

Q: Does Medicare cover continuous positive airway pressure (CPAP) therapy?

A: Yes. Medicare covers CPAP when an overnight sleep study at a sleep disorders center indicates that you have obstructive sleep apnea (OSA). Other requirements vary by region of the country.

Q: I have obstructive sleep apnea (OSA). The treatment I use is continuous positive airway pressure (CPAP) therapy. When I retire at 62, will Medicare cover my CPAP equipment?

A: No. You can receive partial retirement benefits from Social Security when you are 62. But Medicare benefits do not begin until you are 65 years old.

Q: How do I find out if Medicare will cover my sleep study? How do I find out if Medicare will cover my continuous positive airway pressure (CPAP) equipment?

A: Requirements vary by region of the country. Go to


  • Pick your state.
  • Select "Continuous Positive Airway Pressure (CPAP) Device," "Diagnostic Tests and X-Rays", or "Durable Medical Equipment."
  • Click the "View Results" button to get details about coverage, costs and contact phone numbers.

You also can call 1-800-MEDICARE (1-800-633-4227), for more information.

Q: I need to do a sleep study, but I can't afford it and I have no insurance. Is there help available for me?

A: You may be eligible for assistance from Medicaid. This program helps certain low-income people receive medical care. Medicaid is a federal program that is run at the state level. Each state has its own guidelines for eligibility and services. Lean more at

Some sleep disorders centers may help people who are unable to pay for a sleep study. When you call a sleep center ask if it offers assistance for uninsured patients. To find a sleep center near you that is accredited by the AASM, go to