HL7 Table HL70273: Document Availability Status

HL70273 is the HL7-defined vocabulary for whether a clinical document is the one the receiving EHR should be showing right now. It lives in TXA-19 Document Availability Status and answers the chart-display question: is this document the current source of truth, has it been superseded by a newer version, was it deleted, or is it temporarily unavailable. The four values drive whether the receiving EHR shows the document in the active chart, hides it behind a "history" toggle, marks it with a struck-through banner, or removes it from the patient's view entirely.

Purpose

HL70273 separates two concepts that EHRs frequently conflate: the lifecycle of authoring (HL70271, where a document moves from draft to legally authenticated) and the availability of the finished document for patient care. A document can be legally authenticated (HL70271 LA) and still be unavailable (HL70273 UN) because a downstream archive is offline; a document can be obsolete (OB) because a newer version exists, without ever having been cancelled.

Clean separation of authoring lifecycle from availability is what lets EHRs render a consistent chart view across the messy reality of versioned, replaced, retracted, and temporarily-offline documents. HL70273 is the small but load-bearing field that makes that separation work.

Where it's used

• TXA-19 Document Availability Status — the canonical home, present on every MDM^T01 through MDM^T11 message.

Code list

Code system OID

• OID: 2.16.840.1.113883.18.119
• Canonical URI: http://terminology.hl7.org/CodeSystem/v2-0273

The OID is what Vorro emits in CWE.14 when downstream profiles demand OID-bound coded TXA-19 values.

HL7-defined vs user-defined

HL70273 is HL7-defined. The four values are intended as a closed set — extensions almost always reflect a workflow that already maps to one of the four (for example, "Sealed by patient" maps cleanly to UN with an additional security label, not to a new HL70273 code; "Replaced by addendum" maps to OB with the new document linked via TXA-12 Parent Document Unique Identifier). Sites should not invent local two-letter values inside HL70273.

Version differences

• v2.3 — HL70273 introduced alongside the MDM family with the initial set: AV, CA, OB, UN.
• v2.4 – v2.8.1 — Unchanged. Four values, stable for the entire history of the table.

This is one of the most stable HL7-defined tables in v2 — no value has been added or deprecated since the original definition.

Common mistakes

• Conflating CA (deleted) with OB (obsolete). CA means the document should not exist in the chart at all (retraction); OB means it exists but is no longer the current version. The downstream rendering and audit consequences are different.
• Sending UN and never sending a follow-up AV. UN is meant to be a temporary state — receivers may set a stale-availability alarm if the document sits in UN for too long. If a document is permanently unavailable, the correct code is CA.
• Treating an empty TXA-19 as equivalent to AV. An empty field means "the sender did not say"; conformant receivers should hold the message rather than default to available.
• Marking the old version OB without populating TXA-12 (Parent Document Unique Identifier) on the new version. Without the parent link, the receiving EHR cannot stitch the version chain and the OB document looks orphaned.
• Confusing HL70273 (TXA-19, availability) with HL70271 (TXA-17, completion). A document can be AU/AV (authenticated and available), LA/OB (legally authenticated but superseded), AU/CA (signed and then retracted) — each combination is meaningful and must be sent accurately.

Examples

A current, available discharge summary:

TXA|1|DS|TX|202606101430|||||1234^SMITH^JOHN^A^^^MD|||||DOC-99821||AU|U|AV

The same document replaced by a corrected version — the original is marked OB, the new version links back via TXA-12:

TXA|1|DS|TX|202606101430|||||1234^SMITH^JOHN^A^^^MD|||DOC-99821||DOC-99823||AU|U|AV
TXA|1|DS|TX|202606101200|||||1234^SMITH^JOHN^A^^^MD|||||DOC-99821||AU|U|OB

AV translated to a FHIR DocumentReference.status snippet:

{
  "resourceType": "DocumentReference",
  "status": "current"
}

Mapping failure example — unknown vendor code:

TXA|1|DS|TX|202606101430|||||1234^SMITH^JOHN^A^^^MD|||||DOC-99821||AU|U|ACTIVE

ACTIVE is not in HL70273. A conformant engine should quarantine the message, preserve the original code in the audit log, and either resolve through a local remap rule (ACTIVE → AV) or surface for curation rather than silently coercing.

FHIR mapping

The v2-to-FHIR IG does not publish a ConceptMap for this table; the mapping below follows the obvious correspondence, mapping each HL70273 code to FHIR DocumentReference.status:

DocumentReference.status is a code element bound to http://hl7.org/fhir/ValueSet/document-reference-status with only three values, so the v2 UN (temporarily unavailable) has no clean FHIR counterpart. Common practice is either to omit the FHIR resource until availability is restored, or to emit entered-in-error with an explanatory note and re-emit current once the document is back. Either way the original HL70273 code should be preserved as an extension so round-trip back to HL7 v2 retains the UN distinction.

Engine considerations

• Two-character validation — TXA-19 codes are exactly two characters; engines should reject longer payloads outright.
• Case sensitivity — HL70273 codes are uppercase; lowercase av must be normalized or rejected.
• Parent document linkage — When a message arrives with OB and TXA-12 empty, engines should hold the message and require the upstream system to populate the parent identifier; otherwise the chart loses the version chain.
• UN timeout — Engines should track time-in-UN per document control number and surface an alarm when documents sit in UN beyond a configurable threshold (typically 24 hours), since UN is a temporary state by design.
• CWE upgrade path — In v2.7+ profiles, TXA-19 may be transmitted as CWE rather than IS, allowing CWE.14 to carry 2.16.840.1.113883.18.119. Both shapes must be handled.

How Vorro handles HL70273

Vorro validates TXA-19 against the four HL70273 codes on ingest. Values that match pass through untouched. Values that fail validation — vendor mnemonics, display strings, lowercase variants — are routed to the terminology curation queue. Vorro additionally tracks per-document availability transitions: a document moving AV → CA triggers a retraction event on downstream channels; a document moving AV → OB requires the new version's TXA-12 to be present or the message is held.

On outbound, Vorro emits HL70273 as IS for v2.5 and earlier profiles and as CWE with CWE.14 populated for v2.7+ destinations. When a FHIR DocumentReference.status arrives upstream with no HL70273 extension, Vorro maps current → AV, superseded → OB, entered-in-error → CA, and surfaces a warning for any source resource whose original v2 code was UN (because that distinction cannot be recovered from FHIR alone).

Related pages

• TXA segment — Transcription Document Header
• HL70270 code table — Document Type
• HL70271 code table — Document Completion Status

Sources

• HL7 Terminology — CodeSystem v2-0273 Document Availability Status
• HL7 v2 product brief