PD1-16 in HL7 v2: A Field Guide to Immunization Registry Status
PD1-16 quietly feeds public health reporting pipelines — it tells a receiving system where a patient stands with a state or regional immunization registry, and it's a field most clinical test suites never touch because it feels like someone else's problem.
PD1-16 is the Immunization Registry Status field, a coded value reporting the patient's current standing with an immunization information system — for example, actively tracked, inactive, or lost to follow-up. It's paired with an effective date in PD1-17 and is most relevant to public health and registry-reporting integrations.
What this field contains
Example
PD1-16 (A) marks this synthetic patient as actively tracked in an immunization registry, effective on the date in PD1-17.
Where this trips people up
Because PD1-16 rarely affects core clinical workflows, it's easy for test data to leave it blank across the board — which means registry-reporting integrations only ever see the absent-value case and never get exercised against an actual status transition, like a patient moving from active to lost-to-follow-up. Since public health reporting pipelines often treat a missing status differently from an explicit one, that gap can produce silent reporting failures that only surface during an audit.