Modifier N1

The Centers for Medicare and Medicaid Services (CMS) published a Medicare Learning Network article announcing the new N-modifiers for oxygen. The 3 new modifiers for home oxygen use under national coverage determination (NCD) 240.2 and the DME MAC Oxygen and Oxygen Equipment Local Coverage Determination (LCD) and LCD-related Policy Article (PA) were created to indicate the appropriate treatment regimen and presence of supporting documentation for each Medicare patient oxygen therapy group:

The new modifiers are effective January 1, 2023 and will be available in the April 2023 HCPCS code release.

Group I:

  • An arterial PO2 at or below 55 mm Hg, or an arterial oxygen saturation at or below 88%, taken at rest, breathing room air; or
  • An arterial PO2 at or below 55 mm Hg, or an arterial oxygen saturation at or below 88%, taken during sleep for a patient who demonstrates an arterial PO2 at or above 56 mm Hg, or an arterial oxygen saturation at or above 89%, while awake; or a greater than normal fall in oxygen level during sleep (a decrease in arterial PO2 more than 10 mm Hg, or decrease in arterial oxygen saturation more than 5%) associated with symptoms or signs reasonably attributable to hypoxemia (e.g., impairment of cognitive processes and nocturnal restlessness or insomnia). In either of these cases, coverage is provided only for use of oxygen during sleep, and then only one type of unit will be covered. Portable oxygen, therefore, would not be covered in this situation; or,
  • An arterial PO2 at or below 55 mm Hg or an arterial oxygen saturation at or below 88%, taken during exercise [defined as either the functional performance of the patient or a formal exercise test], for a patient who demonstrates an arterial PO2 at or above 56 mm Hg, or an arterial oxygen saturation at or above 89%, during the day while at rest. In this case, supplemental oxygen is provided for during exercise if the use of oxygen improves the hypoxemia that was demonstrated during exercise when the patient was breathing room air.

 

Last Updated Jan 16 , 2023