ICD-10-CM diagnosis guide

Z99.81: Dependence on supplemental oxygen

A status code that reports oxygen dependence when supported by the record.

Educational relationship only. A status code describes a patient circumstance; it does not replace the underlying diagnosis, testing, oxygen order, or coverage requirements.

Documentation questions to research

  • Underlying condition
  • Current oxygen use
  • Objective qualification evidence
  • Continued need where required

Candidate HCPCS research

These links are possible workflow relationships, not a coding recommendation or coverage finding.

Open claim research workbench

Code-set status and official sources

Reviewed 2026-07-16 against the listed CMS resources for the April 1, 2026 through September 30, 2026 code-file window. Always verify additions, deletions, revisions, sequencing, and encounter-specific guidance.