HL7 OCD Occurrence Code and Date
HL7 datatype components OCD components from HL7 v2.5.1 Hide components
These are the generated components for the version selected at the top of the page. The article stays practical, and this panel follows the chosen HL7 version.
Components
OCD combines an occurrence code with an occurrence date. It is a billing and claims-style datatype, often used when a coded event needs the date it occurred.
In this guide, OCD appears in UB1.16, UB2.7. That used-by list is a good reality check: the datatype is only half the story, and the field that uses it tells you the workflow.
The component panel above is expanded by default because most datatype pages are used as quick lookup pages. Start there for the exact HL7 v2.5.1 shape, then use the notes below for the practical gotchas.
OCD-1 to OCD-2: Component Quick Read
The generated component panel above is the formal quick lookup. The short version is below so you can scan the shape without counting carets by eye.
The table-backed components here are OCD-1. Keep those values to the table or value set your implementation guide names, especially when the field is crossing organization boundaries.
- OCD-1 Occurrence Code - Occurrence Code. Type CNE. Table 0350.
- OCD-2 Occurrence Date - Occurrence Date. Type DT.
Practical Notes
Date and time precision matters. If you only know the date, send the date. If you know the time and timezone, agree how that timezone should be represented. In Integration Soup, date helpers such as GetHL7Date and GetDateFromHL7Date are useful because they keep date formatting and parsing explicit instead of hand-built string slicing.
In HL7 Soup Web, click a field that uses OCD and the interpretation view will show which component you are sitting in and where that value lives in the raw message. That is especially handy with compact datatypes because one missing caret can move every value after it.
Official and Reference Notes
For formal reference, compare the generated HL7 v2.5.1 panel above with the HL7 v2.5.1 datatype list and the HL7 Terminology data type code system. Local implementation guides can narrow allowed values, tables, and component usage.