CMS added 3 new modifiers for home oxygen use under :national coverage determination (NCD) 240.2 to indicate the appropriate treatment regimen and presence of supporting documentation for each Medicare patient group:

  • Section B, Group I: modifier N1
  • Section B, Group II: modifier N2
  • Section D, Group III: modifier N3

The 3 new modifiers for home oxygen use are effective on claims related to equipment setup after the effective date of April 1st, 2023. For rental claims related to equipment setup prior to the effective date, DME MACs will continue to accept the KX modifier.