This CPB is revised to state that repeat testing is considered medically necessary for the following indications: 1) to determine whether positive airway pressure treatment (i.e., CPAP, bilevel positive airway pressure (BiPAP), demand positive airway pressure (DPAP), variable positive airway pressure (VPAP), or auto-titrating positive airway pressure (AutoPAP)) continues to be effective in persons with new or persistent symptoms, after interrogation of current positive airway pressure device; 2) to determine whether positive airway pressure treatment settings need to be changed in persons with new or persistent symptoms, after interrogation of current positive airway pressure device. (Note: This criterion does not apply to AutoPAP devices, as they do not require manual adjustments.); 3) for persons with significant weight loss or some other change in the member's medical condition that would affect the need for continued positive airway pressure treatment, to determine whether continued treatment with positive airway pressure treatment is necessary; 4) to assess treatment response after upper airway surgical procedures and after initial treatment with oral appliances. This CPB is revised to state that repeat sleep testing (home or attended sleep studies) for persons getting replacement positive airway pressure equipment is considered not medically necessary unless the member has one of the indications for repeat testing listed above. This CPB has been revised to state that: (i) the Oasys Oral Airway System is considered equally effective to standard oral appliances, (ii) a compliance monitor for oral appliances has no proven value, and (iii) the following are considered experimental and investigational: (a) screening for asymptomatic OSA, (b) voxel-based brain morphometry (VBM) studies for evaluation of OSA, and (c) rapid maxillary expansion for the treatment of OSA.