LOINC Code 77997-5: Legacy case identifier [CDC.PHIN]

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Legacy case identifier. It is commonly used with the system or sample type ^Event.

When is it used?

• Used in lab systems, EHRs, and clinical data exchange.
• May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
• Status: ACTIVE
• Order vs observation: Observation
• Method: CDC.PHIN

What it does not mean

• The code identifies the observation or test, not the actual result.

Key facts

• Legacy case identifier [CDC.PHIN]
• Legacy case identifier
• The legacy case identifier is used by the Centers for Disease Control and Prevention (CDC) to link current case notifications to case notifications submitted by a previous system (NETSS, STD-MIS, etc.).
• Centers for Disease Control and Prevention; Centers for Disease Control and Prevention, Public Health Information Network; Ident; Identifier; Nominal; Point in time; Random; Survey; SURVEY.CDC

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Frequently asked questions