AR-DRG ICD/ACHI/ACS mapping registry
This content is for 2025. Switch to the latest version for up-to-date documentation.
AR-DRGs are derived from admitted-acute episode data, not stored as a raw input column. The classification depends on ICD-10-AM diagnosis codes, ACHI intervention codes, ACS coding standards, and versioned licensed grouping tables or software that turn coded episodes into AR-DRG outputs.
This page describes the registry and provenance layer around that process. It tracks which versioned inputs and grouping assets are expected for a pricing year, but it does not reimplement the proprietary grouper.
What the registry records
Section titled “What the registry records”The registry is the public metadata surface for version compatibility and provenance.
| Registry field | Purpose |
|---|---|
| Coding-set family | Identifies the ICD-10-AM, ACHI, ACS, and AR-DRG families in scope |
| Version | Pins the exact released version used for the pricing year |
| Effective pricing year | Shows when the version applies in a costing study or release |
| Input dependency | Records which coded inputs must be present before grouping |
| Grouping asset reference | Notes the licensed grouping tables or software release used locally |
| Source reference | Points to the authoritative publication, catalog entry, or release note |
| License note | Captures redistribution and usage limits |
| Provenance note | Explains how the version was chosen and validated |
The registry should make it easy to answer three questions:
- Which ICD-10-AM, ACHI, and ACS versions feed a given AR-DRG version?
- Which pricing year or transition boundary expects that combination?
- Which local licensed asset was used to produce the grouping output?
What the registry is not
Section titled “What the registry is not”The registry is not a substitute for licensed AR-DRG grouping software or official grouping tables.
- It may describe the inputs, version boundaries, and provenance of a grouping workflow.
- It may record that a local user supplied a licensed grouper or table set.
- It must not publish restricted grouping tables, redistribution-limited packages, or a proprietary grouper reimplementation.
- It must not imply that the repository can generate authoritative AR-DRG outputs without the licensed version-specific grouping asset.
Supported workflow modes
Section titled “Supported workflow modes”The public docs support three AR-DRG workflow descriptions:
- Precomputed AR-DRG input, where the grouped DRG is already supplied and the docs only validate provenance, version alignment, and downstream use.
- Local licensed external grouping, where a user supplies their own licensed command, service, or file-exchange process outside the repository.
- Metadata-only provenance, where the docs describe the versions, pricing year, and local asset references without claiming bundled grouping logic.
These modes are intentionally narrow. They let the repository explain how a study or workflow can use AR-DRG outputs without bundling proprietary grouping logic or implying that the public docs can replace the official licensed grouper.
Costing-study implications
Section titled “Costing-study implications”For costing studies, this registry is useful because AR-DRG comparisons are only meaningful when the coded inputs and grouping version match the study year.
- Report the ICD-10-AM, ACHI, and ACS versions alongside the AR-DRG version.
- Record the licensed grouper or table release used to classify episodes.
- Treat version changes as methodological changes, not just documentation details.
- Avoid comparing episode-level costs across studies that used different grouping versions unless the study explicitly reconciles that difference.
- Treat precomputed AR-DRG inputs as study artifacts, not as proof that a separate implementation matches the official grouper.
- Use the registry as provenance for the study method, not as evidence that two independent implementations produce identical grouping results.
This matters for benchmark studies, AHPCS-style reporting, and any analysis that compares observed costs to AR-DRG-based pricing. A mismatch in coded-input versions or grouping version can change the DRG assignment and therefore the costing result.
Appropriate-use caveats
Section titled “Appropriate-use caveats”- Do not claim parity with the official grouper unless that parity has been separately validated.
- Do not infer that a public metadata registry can replace a licensed grouping product.
- Do not redistribute restricted input tables or software through this docs site.
- Do not mix public provenance records with claims about executable support.
- Do not present local command, service, or file-exchange integrations as a bundled implementation of proprietary grouping logic.