← ReferenceStandards
What is a Profile?
A Profile is a StructureDefinition that constrains a base Resource for a specific use case. Profiles define what elements are required, what values are allowed, and what code systems must be used — without changing the underlying FHIR specification.
For example, the EHDS Patient Summary profile constrains Patient to require a national identifier, specific name elements, and a set of must-support conditions. A resource that follows this profile is valid FHIR R4 and valid Patient Summary.
What a Profile can define
- Cardinality: make optional elements required (1..1) or restrict repeating elements (0..1)
- Must-support: elements that systems must be able to store and return
- Fixed values: lock an element to a specific value
- Binding: restrict a CodeableConcept to a specific ValueSet
- Extensions: add new elements not in the base spec
- Slicing: define multiple sub-types of a repeating element (e.g. different identifier types)
Implementation Guides (IGs)
An Implementation Guide bundles profiles, value sets, code systems, and examples into a publishable specification. Major IGs include the International Patient Summary (IPS), US Core, and the upcoming EHDS EHRxF IG.