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S8121 HCPCS Level II Code: Oxygen contents, liquid, 1 unit equals 1 pound

HCPCS Level II code, maintained by CMS. Not a CPT code: CPT (HCPCS Level I) is a separate AMA code set that MedCoder does not publish. About HCPCS Level II

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Medicare Coverage & Payment

  • CMS short descriptor: O2 contents liquid lb

Source: CMS HCPCS Level II release. Coverage codes indicate how Medicare treats the code, not whether a specific claim will be paid; payer policy and documentation still govern.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Contextual Map

Every relationship of S8121 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Nearest codes (9)

Change history

  • October 1, 2003 — Added to the code set [Change history]— CMS release files (code change ledger)

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, descriptors, coverage and pricing attributes Official source data
CMS HCPCS Alpha-Numeric (ANWEB) release — October 2026 quarterly update Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS HCPCS quarterly update files, ingested into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder-derived relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder editorial explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 20, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "S8121 — Oxygen contents, liquid, 1 unit equals 1 pound." HCPCS Level II October 2026. https://medcoder.ai/hcpcs/code/s8121-oxygen-contents-liquid-1-unit-equals-1-pound

Change history

  • October 1, 2003
    Added to the code set
    Oxygen contents, liquid, 1 unit equals 1 pound
    HCPCS 2003 changes

Nearest Codes in This Family

Official HCPCS Level II classifications closest to S8121 in its code family, with their registry titles.