Version Differences

What changed between an HL7 v2 version and the one before it

Each version is compared against its immediate predecessor, field by field. This answers the question that comes up during every upgrade: what actually changed, and does it affect the segments I send?

What Gets Compared

ChangeMeaning
RepetitionsA field’s repeat limit changed
DescriptionThe field’s published description was reworded
Table IDThe field’s bound table changed
New rowA field was added to a segment
New componentA component was added to a data type
Data structureThe field’s data type changed

v2.5.1 against v2.5 is a good illustration of the scale: 52 changes in total, 51 of them in segments across 22 segments, and a single data-type change. Most are repetition-limit changes, which are exactly the kind that break a receiver quietly.

Filter by kind

Show everything, or narrow to segment changes or data-type changes

Old and new side by side

Each entry carries the previous value and the new one

Linked to definitions

Jump from a change straight to the segment or data type it affects